|I can only speak for myself, but my preference has always been to use a plain text editor such as notepad and upload via ftp. |
A lot of the errors returned by the validator could be caused from it using the wrong doctype to start with. Before rewriting your page, I'd mill over the help files of whatever program you used to see if it will add a correct doctype for you, and then try the validator again. Actually, I'm surprised it didn't add one... maybe it's an xml thing? That link has an example of a valid declaration about halfway... I don't really know much at all about xml docs. If you still get a lot of errors, then perhaps try something else. There are several freeware and a few commercial editors available here
I don't know how many links your site had, but when I tried them using Mozilla Firebird 0.7, the left menu appeared to work fine; however, if there were links in the right pane or bottom, then they weren't working.
Hope that helps.