I love the changes you have made to the class.
Personally I feel that Master of Your Trade is a touch to powerful it makes it pointless to buy new skills when you can just buy 2 feats to get a +4 to all unknown skills as opposed to taking Skill Training twice and getting trained in 2 unknown skills (a +5). Instead maybe just +1 to all unknown skills which stacks with Jack of all Trade.
Thanks for the comments!
Don't forget that Master of Your Trade only applies to untrained class skills, not to all untrained skills. This means that Jack of All Trades would give an Historian +2 to 9 different skills, while Master of Your Trade would only give an Historian +2 to 4 different skills (raising only those 4 skills to a +4 if both feats were taken at the same time).
(regarding Aberrant Master...) I also don't think they need their own power type since starlock tap into the same type of energies and use arcane I feel that arcane works for these. Needs some kind of implement to keep these powers in line with all of your other ones.
Of couse, the "alien" power source is just flavor since power sources have no actual impact in the game. Anyone who prefers that it be Arcane can certainly change it with zero effort.
That said... the reason I went with a new power source is that I want aberrants to feel very different (well... I want them to feel alien actually ), and I just don't get that feeling off of slapping arcane on it. As a secondary benefit, it also helps distinguish Aberrant Master from Arcane Historian.