Re: NATASHA/BUCKY.
Take him. He's a powerhouse, fast, and quick thinker - all of which you know. He heals faster than most, so instead of a team of normal humans, I'd say he's an asset. Plus, he already has grumpy ass' training instilled him like the rest of the portal guards, so he'll work on a team, even if he wasn't an Avenger.
But yeah, younger Steve's going to be a real pain in the ass about this, so comms is a good place for him. His big brain will come in handy.