Ah yes, I just looked at the content of those files, and to answer your first 2 question's... It looks like there is one old version of the jquery library(jquery-1.3.2) you can probably throw away. File name: jquery_002.js.
There are 2 other files for JQuery.localscroll and JQuery.scrollto functionality(never tried those myself); it looks like they could be combined without conflicting with eachother: jquery.js + jquery_003.js. It's hard to say, for sure, until you test it.
After that, you'll be down to 2 calls to the server: one for the JQuery library, and one for the extra functionality on your page, this is good, really.
It's hard not to get angry when you're having issues with IE. I think this is one of the big reasons I started using JQuery actually.