For background on this issue with my 99 Blazer, search for "Problems with Chevy Blazer" posted early this month.
The reason it has been locking up and dying on me is that my catalytic converter is plugged up, according to the shop anyway. Not sure if that is why it is causing the other problems since I don't know a lot about cars, but it is something my dad said he could handle.
Anyway, I'm glad to konw that it isn't anything major, and that now I will have that rattle in my exhaust fixed. :)
Thanks to everyone who posted originally and tried to help.