I like Michael Bennett and for the right dollar amount I would take him back no questions asked. He's still young (28) and in his prime, so if the Hawks can get him on a 2-3 year deal for 5-7 mill a year then I hope it happens. If another team wants to give him a 3-5 year deal at 7+ million a year then I would guess he's as good as gone. I like some of the other young guys mentioned (Hill, Brooks, Scruggs and McDonald) to step in if Bennett leaves (but none are in his league (yet)). I would also guess there may be a vet or a rookie brought in as well (for cheaper), so the loss of Bennett would suck, but if his cost is to much then you have to go with the whole next man up motto.
As far as Tate and the Mc D twins go, I would take all three back. But once again there will be teams that toss dumb money at guys on winning teams. So once again if the money's right I would take all three back, but you never know what teams like the Raiders, Cowboys, Redskins, lions, etc. will toss at a guy.
All four guys would be great to have back, but that's not going to happen (plus you still have guys Breno, Baldwin (RFA) and other guys that need new contracts and restructures). Another solid draft would help a lot too.