I am not going to do it but I think I have read other people killing it but it restarts itself shortly there after...

Just do it. The worst that could happen would be like the final scene in Fight Club

http://www.youtube.com/watch?v=XkUaV9GZDuk

 

I've stopped it before using System, and basically it just restarted itself. I think rooting it is the only way to turn it off completely.

 

If you force stop it while you are running another launcher by default, it won't restart...unless you clear defaults for the downloaded launcher and press home again and select HTC Sense.

I just did it.

 

Clearing HTC Sense data will just reset Sense to the defaults. You will have to reset your home screens but you will not lose any app data or applications.

This is how most FC's on Sense are cleared.

Force stop will just stop and restart it.

 

just did it now while running launcher pro. hope that the world does not end... but it seems to make sense right, i don't want to run 2 launchers at the same time because it can't really use them at the same time.