1. End FP after the last convo with droid/ship captain, then people can hit 'exit area' button and choose 'previous location' like with any other FPs. Yes, you lose out on 2-8 social points, but comparing to the potential loss of time on getting back to where you were, it seems to me as acceptable tradeoff. Also, it may eliminate the crashing problem, since most people crash on that traveling conversation. So, no convo = no crashing.
Instead of that, what they really should do is end the Flashpoint at killing the last boss and give your daily rewards then and there.
There is no point forcing people through another 4 separate painfully long conversations on FP that has too many of those already.
Anybody who wants to see the story, can then just do the last conversations on his own while others leave. You don't need a full group to do what is nothing more than a conversation cutscene.