2) The CSS doesn't choke anything up. By properly using HTML 4.01 Strict and CSS you end up with a page that works on all browsers.
That is not necessarily true. I can make a page using CSS 1 only, that looks great and works in Netscape 7/Mozilla and it will not work cross browser without applying "hacks".
If you really want a site to be compatible with 3x or 4x browsers the best you can do is to use a 4.01 transitional doctype and use depricated tags that are allowed only in that doctype.
I would be interested in seeing a site with one stylesheet, no browser sniffer or redirection to alternate pages that works in all browsers, that is not extremely simple layout. Like maybe one div......LOL
For my business site, I still have people using 3x browsers to visit and I cannot afford to have them get a "text-only" version of the site because somebodies standards are saying HTML is out.