Please find the technical audit findings below - nothing awful found - it was quite a difficult crawl to only section out a subfolder and to make sure I captured it all. I have been going through similar websites/competitors and I feel that your proposed sitemap works very well. I think a form of sorts will be great so that people can sign up to stay up to date with news and publications etc. And then when creating the pages the more information on the page the better chance of ranking. So don't be afraid to build those pages out and add FAQ sections :)
Here's a little snapshot of the improved Keyword Growth they currently have:
And their top traffic driving pages:
When creating the new site it will be in the best benefit to make sure that the new pages for these Top Pages carry the same info PLUS more in order to keep their keywords and then improve from there.