Yes, it is possible to bring the droid all the way to the end of the level. Is it advantageous? Not in the slightest bit, unless you enjoy watching him sit there sulking as you fly away in the Queen's Ship.
Well, what your girlfriend is explaining is a penchant for more adventure-type games than the all-action variety. It's a matter of taste. We put TPM together as a conglomeration of several different styles, and while a lot of people liked it, others did not. As to whether games SHOULD be geared towards people who play other sorts of games, well, who knows. You can, but you risk turning off other gamers.