Ok, I made it to lvl 15 and hit a crash, all normal up there... I restarted my game and waited until I went to lvl 16 before speaking to Kreia, this preety much solved the problem, also, I (finally) understood how the whole process works, you build your character with all the bonuses of jedi guardian and jedi consular then you go and get your prestige class, and then you perform the "pure breed" to get any feats and powers you missed as a jedi guardian.
By the end of it you are capable of chopping anyone in your way and still have a decent fight with some enemies.
Thanks for your help.
There is no slauther without laughter