Have you tried DaVinci? I know some people get on well with that.
My experience with Vegas is that is doesn't play well with 3rd party plugins. If you have tried scanning a folder with VSTs or audio plugins, that may be what is causing it to crash. The experience I had was that I included my DAW VST folders in the Vegas plugin scan and it completely *****ed up some of the VSTs - I had to spend most of a week figuring out which VSTs had been effected, uninstall them, and reinstall them. I learned my lesson the hard way. Now, I keep my plugins to a minimum when using Vegas, and I do any audio processing outside of Vegas, not inside.
I guess it's the age old problem of using your laptop for multi-tasking. You should really have a machine dedicated for Audio, another for Video, and another for internet - but we can't afford to fill our houses with laptops, can we?