I think browser thingy is not a big deal (if we are talking about not getting it to work in IE6 :P. but if a website works in all IEs but no other browser I'll kick the shit out of the developer).
Another mistake: thinking you can design a website even while not being a designer.
No contact or / and about page is fucked up to. Most new sites I visit and don't really show what they do / are / want, I want to visit their about page first and read the goals of the site. If that isn't available I most likely end up still not knowing what the site is about and leaving and never coming back. It's sad but true... On the other hand, if the site just shows what it does with it's content, I stick around faster.
those are my 2 cents...