If it comes to it, would Vince even get claimed on waivers? I still think he's a perfectly fine 5th starter but for what he makes, and as a pending free agent, he doesn't have value to a lower-budget rebuilding team, except as a possible deadline flip. And if that's possible it may as well be us. No real reason to think Hale would have trade value, he's been DFA'ed so many times, and now he makes a bit more money.
If they weren't seriously committed to the idea of needing two long relievers (one of whom can also start) they could have kept Watson. If they wanted Romero just because he's lefthanded, they would have kept him over Coonrod. Maybe in two months all the starting pitchers will be healthy and regularly pitching 5-6 innings and things will change but right now Hale and VV are on the team because Girardi wants them on the team. They'd certainly be better off if one of the players in that role was a guy with options
I don't think there is going to be any rush to bring Kingery back. This isn't just a situation where he can fine tune for two weeks and then get back on a track as a bench player, and there won't be that much challenging or sufficiently regular work in April either. It'll be at least a couple of months (one at the alternate site and one in actual AAA games).
Presumably they are trying to figure out which guy they can actually trade, possibly without even going through the DFA process (but they could still make a trade then too).