That is a bit drastic. an Archive an Install might be a less destructive method of getting a clean[er] system.
I would certainly troubelshoot this more before reformatting a computer...
How often are programs crashing?
what are some sample error messages you are reading when the applications crash?
If you are a new mac user, you might enjoy knowing that Command Shift 3 will take a picture of your screen for later reference.
SnapNDrag is nice freeware that helps with...