I think that by "support" tyro meant supporting TAs, etc. You must have not only the giant adjacent to the friendly character but the character adjacent to the giant in order to use TAs such as SinSyn/Bat Enemy/Defenders etc, which could be considered supporting TAs.

Giants really need flight, charge + movethrough, Leap/Climb, or Phasing to function in this pog ridden meta of ours. As mentioned before, they just get tied down to easily.

My vote for cool upcoming giant? Rita Farr. I think Outsiders is going to come into it's own for cancelling all the pumps that will be necessary to hit the 17 defense average floating around while simultaneously making the target easier to hit for your team by cancelling ES/D and CR. Rita can do this while ignoring other characters and still control a large portion of the board.

He'll also be able to taxi in someone while moving. That's pretty standard fair for fliers, but for a Giant it means you can carry around a support piece. It can make a world of difference.

Can they attack a character 2 squares away with a close combat attack?

Yes. That is one of the biggest reasons to play a Giant: reach out and touch someone, so to speak