RobertS

There is actually. Under manage account. Close account. 

For the categories. I'll look into this more. Thank you for the feedback. 

No. If I want someone to help with SEO I won't be looking on SM or map listings.
If the directory is about finding referral partners maybe change the categorisation to limit which business type can join.
But this sort of thing has been tried many times before. I've joined dozens over the years to see if they work and they don't. But I have found some great partners on freelancer sites.

Easy to answer this one. It’s because they don’t know how to do seo. What do you mean by sites they don’t control?

As long as they have access to the site files they can do seo. 

Some will refuse to work on sites they don't control because they don't know how bad the underlying site or code is. It could be built with a page builder and the efforts may not be worth it. There's also a risk that the external developers could undo your work, or could affect what you have put in place. Strategically it often makes more sense to handle everything on a single side IMO.

I am not sure if the understanding of SEO is correct here. A SEO analysis you page, the traffic flow, the link structure, rankings, CTRs, SERP features, loading speed, structured data, images, videos, semantics ... just to name a few. For this the SEO needs data from sources like GSC, Analytics, Matomo and other tools. 
This will result in recommendations to improve Ranking, Traffic, CTR and conversions on your page. The implementation of the changes in normally up to your inhouse content and dev team. 
If you want the SEO (no matter if agency or freelancer) to make the changes, because you don't have the resources for that, than it is something different. They will need their own content writer and have to understand how to implement the changes (But this should be no biggie in any CMS). If your page is hard coded using a Klingon version of C++ , than I wouldn't be too surprised that they tell you that they can not be of any help. 

No there isn’t. In fact the keywords meta tag is redundant and has been for years.
If you don’t want to get found for a keyword just expunge it from the site. If it’s not there google can’t rank you for if.

Oooh yes that's tough when you have a client with no people skills (or a power merchant!).
Contact forms asking for "too much" or irrelevant/sensitive information is a regular one for me as well. In the UK we have GDPR to take into account (mentioning legal issues for sensitive info usually makes clients think twice!). Over the pond you have the CCPA and others to take into account - maybe your client wasn't aware of that?
Follow orders or do what is right? Tough one. Sometimes you have to bite the bullet and do things the clients way, but if it's a difficult problem like you had I'd consider doing what they ask but provide a written disclaimer to say you're not responsible for any negative outcomes.

I think it depends on the subject.
Certainly if the client was asking for something unethical or in an illegal grey area that'd be a red flag and a sign to walk away.
Conversely if we're talking things like design or content presentation/structure then its your choice how to proceed. We all end up doing things the way the client wants sometimes, even though we recommend something different - in situations like this describe how your solution would work vs the clients solution and let them decide how to proceed - they are after all paying the bill.
Like @davep said, you don't have to add the site to your portfolio.

you can just walk away amicably or then do it for the normal price you would charge but make sure you have a contract in place, you get a deposit (1/3 or 1/2) upfront before starting, and make it clear that you're willing to do it even though you don't agree with it. don't use it in your portfolio or put your name to the project either. (this is assuming you've gone into a detailed explanation of why your way is better for THEM).

Got an email (not from anyone here - I hope). Not a direct quote but the jist of it is as follows....

"I want you to build for me a website. I want it to look like this. And I want you to include in your price cost of hosting." 
After I sent him the quote (not including hosting but included an estimate of what hosting would be paid directly to the host)....

"Ok. Sounds good. I'll send you $3350. You can keep $350 and send $3000 to my graphic designer for the content and logo. Ok?" 
My reply. "Um, No thanks. Not how I do business. Thank you. ". 
Sound familiar to anyone? 

Got an email (not from anyone here - I hope). Not a direct quote but the jist of it is as follows....

"I want you to build for me a website. I want it to look like this. And I want you to include in your price cost of hosting." 
After I sent him the quote (not including hosting but included an estimate of what hosting would be paid directly to the host)....

"Ok. Sounds good. I'll send you $3350. You can keep $350 and send $3000 to my graphic designer for the content and logo. Ok?" 
My reply. "Um, No thanks. Not how I do business. Thank you. ". 
Sound familiar to anyone? 

Got an email (not from anyone here - I hope). Not a direct quote but the jist of it is as follows....

"I want you to build for me a website. I want it to look like this. And I want you to include in your price cost of hosting." 
After I sent him the quote (not including hosting but included an estimate of what hosting would be paid directly to the host)....

"Ok. Sounds good. I'll send you $3350. You can keep $350 and send $3000 to my graphic designer for the content and logo. Ok?" 
My reply. "Um, No thanks. Not how I do business. Thank you. ". 
Sound familiar to anyone? 

Update - I have my web design client back. Although under a different domain name because the buggers decided to transfer it to their own reseller account - and didn't bother (thankfully) to cancel the old hosting account. 
New domain purchased under existing account, attached to existing hosting, SSL repurchased (expired), and we are back live in under an hour - because I still had the old files. :-)

#CustomerService

Update: So as customary I sent the website performance reports per the contract. (so I can deliver on the contract for as long as the payments are going through). I ask my client if they are satisfied with the new website. Turns out they are NOT satisfied with their new web designer. 4 words dear client. 4 words...

No I did not tell them that but did offer to regain control of the website. I only need access to their hosting account and I can reupload the files. 

Stay tuned...

That's an interesting twist in the tale, keep us posted!

Update: So as customary I sent the website performance reports per the contract. (so I can deliver on the contract for as long as the payments are going through). I ask my client if they are satisfied with the new website. Turns out they are NOT satisfied with their new web designer. 4 words dear client. 4 words...

No I did not tell them that but did offer to regain control of the website. I only need access to their hosting account and I can reupload the files. 

Stay tuned...

There is no average. Like @BlueDreamer I’ve got clients from years ago and some who moved on soon after the project was completed. And some who I never want to work with again.
The functional projects tend to have better retention than those where design is the focus.

Get Akismet installed and link this to the contact form.
You can also set up filters in your cPanel to block all sorts of things.

You don't have a captcha to prevent spam bots from submitting the form on your site. You need to add something like the following:
A honeypot script (a hidden field that spam bots will fill out, that if done so prevents the form being sent)
Google reCaptcha - https://www.google.com/recaptcha/intro/v3.html
hCaptcha - https://www.hcaptcha.com/
Also, I noticed your site uses a plugin called Contact Form 7. You can find plugins that help with this specifically for Contact Form 7, such as https://wordpress.org/plugins/contact-form-7-honeypot/ and https://contactform7.com/recaptcha.
 

That's a hard one to answer. I've got clients that have been with me for 15+ years, some 10+ years.
Some clients move on after a few years, often if they close their site or business.
Some clients simply move to different developer after a year or two, some come back when the move wasn't successful.

Snap, and on this note always keep a copy of the site. I've had clients come back after their new designer broke their website, a working copy is a God send.

What other have said, but here's my take:
Sometimes clients just move on for a myriad of reasons, don't take it personally. As Jack said they can get swayed by a "cheap" offer or sales talk.
If a client leaves me I tell them I'll leave the door open should things go tits up - I've had more than one client over the years come back because things didn't live up to the promises they were made.

Your job is done.
Except to get paid.
You don't. You move onto the next project.

Generally you don't, but there's nothing stopping you from playing the long game and winning back the client. If they have been reached by a cheap, spammy company, then it's only a matter of time before they start making costly mistakes. A contract can buy you time as you both have an obligation to fulfill a period of time, you might be able to claim back expenses if a contract has been ended abruptly and you have clause within your contract that stipulates a notice period. Sometimes you will lose clients though, that's just what happens.
At this stage the client has made their mind up regardless, the best you can probably do is email saying you're happy to transfer the website once outstanding payments are made (if they have any) and if the company turns out to not be beneficial or providing worth, you're happy to assist them with the same work in the future.
Sometimes this happens because a client isn't aware that you offer a particular service too. It doesn't hurt to have a look at how you're marketing yourself and your services. If you don't do SEO, then it might be worth looking into a reliable freelancer that can work with your clients. We did this at the previous agency I worked at, we didn't offer SEO but we partnered with a company that specialised in it, we would get the dev work and we would forward any clients interested in marketing to them and it worked out well for both of us. It's probably harder to do nowadays but it's not impossible.