Rudi

Hi all, 
I am a little bit exited. I have developed a new schema markup generator, that other than all other that are out there at the moment, includes entities and their validation via an authority link. You can also (again first with this tool) mark up a webpage hierarchy.
At the moment it only is available for FAQ, HowTo and Website/Webpage.
Would be delighted if it helps you and if you let me know your thoughts. Also what kind of schema (product, event, recipe ...) should I work on to include next?
Just have a look at the launch blog post, it is all explained in there: 
https://www.20i.com/blog/schema-generator-with-entity-and-hierarchy/

Your suggested layout would be a custom template which means you need to do some coding (or pay someone to do the coding). 
You might be able to recreate some of that using blocks but in reality you are combining three different theme components: header.pho, home.php and footer.php
Also worth noting is that layout isn’t going to work on a phone (which is what most people use).

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.