Can Update.microsoft.com be accessed with IETab?
You should be able ton. The screenshot that the authors of the IE Tab provided shows them updating via Microsoft Windows Update through the IE Tab (that was on XP or some other version of windows requiring Microsoft Windows update via browser)
I hate to say that I do. I have used FF before and didnt like it, also my one friends sister slaped it on her machine and she had all sorts of issues.
Well, for every single application / software that has been made up to date, I bet that there will be at least one person whose computers are going to have problems with it one way or the other. So, for every web browser out there, there is at least one person whose computer will have problems with it.