While I think having the creators return would be awesome, I'm sort of against it because while Takaya isn't that old he is prone to taking long breaks and I don't think i could handle waiting. He's also not that young either.
I think with saying who's good and who's bad, you have to look at the morals of the day and the personal morals of yourself. Obviously by normal western standards taking over the democratically elected governments is bad, but it's sometimes been argued that a benign dictatorship is possibly the best form of government. Let's be honest here, a lot of our governments are on 3-4 year terms and they pick policies which make them popular now rather than those that might be better suited for the future. Being run by immortals, Cronos can take the long view, infact they have to take that view.
Agito has definitely been an antagonist from the moment Sho got the Unit. Before that, he was indifferent to Sho. Cronos is by the very definition of antagonist the antagonists because they are 'against' the main character. So regardless of how good they are, no matter which Zoalord it is, since they are all under orders to bring in at the best, Fukamachi, they are all antagonists.
Perhaps the better question would be as suggested, who is the amoral or 'evil' people in the series?