I use Sony Vegas for all of my stuff - It's the sort Premier-lite I guess. It still does everything I would want and it handles DV/HD etc really well. And there are some decent tutorials out there for fun/cool stuff as well!
In Vegas you should be able to whack an alpha channel logo on the top of the video layer so its transparent etc, and you can render to all sorts of quality settings, mpg1, mpg2, avi etc.
I'm still on about Video editing.. AS IN THE SUBJECT
There's no way you can hack MSN accounts. Although there is a program which pretends to be MSN and tricks your friends into entering their information..
But to be honest, I don't see why you'd want to be sad enough to hack someone's MSN anyway.
Adobe Premiere is really an easily accessible although expensive editing software, vegas is superior but harder to get the hang of. to be honest if all you want to do is add txt, Movie maker is your best option although sadly it looks somewhat un-professional