I know this is unpopular, but I always liked Freitas as a fighter & individual, much as I am fond of Katsidis for his latter-day heroics & commitment, as well as his excitement (something Freitas also once brought). I do think he gets a slightly unfair beating in the eyes of most for the drubbing against Corrales, but it did all but ruin his career. Still, I see him as a cut above Katsidis as a fighter --- but in a bout of punchers such as these, that can matter not very easily. I would honestly take Freitas if pushed, but it'd be silly to put a line through Katsidis' name. Interestingly, they do share one common opponent, in Joel Casamayor. Refereeing controversy was present in both bouts, to varying degrees.
Freitas is just a better all around fighter. I think he takes out Katsidis in the last quarter of the fight.
Tough to say. "Prime Freitas" means 130, which makes this a P4P matchup, which I hate. But playing by the rules, I'd have to pick Freitas in that instance, probably by late knockout. Katsidis' blatant disregard for defense would be too much of a liability to overcome in this one. At lightweight, I'd take Katsidis by knockout/quit stoppage and not even think twice about it.