Could a outlaw tech or tinker use their abilities to modify cybernetic implants? Say someone wanted to kit out their cybernetic army like Bao'dur's in Knights of the Old Republic...

There's nothing in the RAW on this count, but I don't see it as unbalancing to allow some sort of minor built-in advantage, along the same lines of built-in equipment for droids.

I would say that anything that is not in the rules, is for you and your group to decide.