OK I found that using the Both gender Mod running around, and playing a female will give you All the romances. . Carth Bastila, and Juhani.
I also did not change the class.
I waited till I could become a jedi, before leveling my Main char.
Once I got to dantooine, I ubered everyone with feats and skills, and powers, and etc. I did not play with XP.
So far so good, one starmap to go and No breakage there.
OK so we have figured out that making you're self a Jedi before it's time, and the gender option will break the game.
Well now we know.... And knowing is half the battle.