The type size isn't so much of an issue (I'm guessing your target demographic is at the elderly, possibly sight-impaired end), but it's also true that for that audience you probably want to stick to convention as much as possible - ie keep the nav either at the top or on the left of the page.
The nav panel could be narrower too without decreasing the font size.
The endless grey is a little stultifying.
The body type could be a little darker for better contrast.
A bit more leading would make it easier to read too.
The logo could do with a little more breathing space around it.
Put your basic contact info on the bottom of every page - not only does it lend the site a little more authority and credibility (by declaring who and where you are, that you're a real company with a real address), but this is also a demographic that likes to print out and it's much handier for them to use the contact phone number on the page than have to go back to the site to find the contact page (which they probably didn't print).
I find FAQ pages a lazy way to dump answers that should have been answered in the main pages. If they really are FAQ, then it should be obvious from the section titles in the nav as to where they are answered (eg. "How does it work?" "how much does it cost?" "how safe is it?" "do I qualify?").