You can but it's really not worth it IMO. You'll have to change all related systems. Then you'll run into problems for sure. There's always problems to be sorted out with a swap. I'd just buy a turbo car and be done with it. For more info visit http://columbusdsm.com/
Yeah, probably wanted to let you go home first and wait so you'd get freaked out. That way his message would have a bigger impact. Cool for you though, lucky.
It's gone. But you don't need it though. If you change something in your profile, all you have to do is look at any of your previous posts to see the change. You can even preview your sig before saving.