So I've just finished my Light Heavyweight fighters career and decided to put him to the test online in a Quick Match. I had finished career with the LHW title and when the fighter into's happened I was introduced as the Reeeeigninggg, Defennndinggg Light Heavyweight Champion of the Wooooorld. Also, the referee during instructions mentioned that the fight was FOR the LHW Belt.

So if I lose a match online now as the champ, do I lose the belt? Seems like a dumb question, but I just have to know for sure.

Possibly. I went up against this guy using a regular UFC character and he was using his CAF. He seemed to know what he was doing and I thought it would go down to a decision in the 3rd round. But then I heard the commentators say this is a 5round match since its for a title. After I beat him, and during teh belt ceremony showing the winner, the guy disconnects on me.

I "won" a championship online... the Lightweight one in fact... but it didn't seem to effect anything other than the cut scene at the end of the match.  

Yeah when u set the cutom settings for 5 rounds that atomatically means you will fight for a the championship in any way weight class, if you want a rehular match just go with 3 rounds.