I might just be better off nailing down exactly what I want in the navbar and going back to individually placing the bar on each page
I think its worth noting that accessibility is meaningless if you don't actually have a site that you update and work on; and you'll only update and work on a site if its enjoyable and not a hassle for you to do; you are the important person, not your visitors.
So this is definitely an option, but it's also a lot of extra work; if you find that extra work is putting you off web design, then it's much better to take an easier approach like iframeing and accept that it won't suit everyone.
Screenreaders will always improve and there's no technical reason they can't be designed to understand iframe sites; but if you create a situation where your site is so much work that you give up, then the best screen reader in the universe will never be able to read it and that's much sadder
