1. Is there a maximum amount of powers/combat abilities/team abilities that Amazo can use?

2. Since he's using them: can he use uncopyable TA's?

3. Does he just keep the abilities until he is KO'ed or the game ends?

Thank you.

1. 3 is the maximum as defined by his text: Amazo can use that power or ability and, if he can use 3 powers or abilities in this way, he must stop using one before choosing a new one.

2. He's just using(not wild carding or copying) the TAs so he can use uncopyable ones.

3.KO'ed I would imagine.

Out of curiosity, why would it matter if he kept them after he was KOed?

Black Talon can "bring him back" for an attack among other things... there's also options like Lazarus Pit and Z-Virus that could be impacted by the question.

FWIW, I agree that it should go away if he is KO'd.

And people say this game is too complicated!

The question had more to do with the length of time he kept the powers...is it one and done or does he take and keep them for the duration of the game.

I asked because it doesn't define it as a max...it could also be taken to mean if he can use at least 3 powers or abilities in this way..

Not really. The next part says that if you already have 3, then you must stop using one to pick up a new one.
In other words, if you have Amazo copying Tiny Size, Great Size, and Sharpshooter, then you are copying 3 things. In order to get a new one, then you must stop using one first.

So on 3 consecutive turns he can take a free action to copy 3 powers and/or abilities and/or team abilities. On turn 4 he stops using one of those to pick a new one...is that right?

If he so chooses, yes. If I'm playing Amazo and I choose Invincible, PW, and RS on 3 consecutive turns, I may not be choosing a different one the whole time after that (depending on the team I face and the situation, of course).
You can't choose to keep more than 3 powers, but he could choose to stop using one of them every turn to take a new power after that.

Thank you!