I believe if you like the character, you should get it. That’s all what this game is about, playing with your favorite marvel characters. So I would recommend hulk buster since it makes him usable.
If you’re planning on getting t-3 mag, then get his uni. Otherwise, it’s pretty lackluster.
Wasp uni is pretty good for the reasons you said. Also helps with GBR and AC. So that’s makes her relevant for 5 game modes which is worth imo.
If you’re still trying to finish all 30 stages of SL, then IW RR has more value. If you can already easily do SL, then the stat boosts from falcon are more valuable than maybe using rocket once a week in SL.
Also, would definitely save for Sharon Rogers and Luna’s uni from next update if you use them.