I've dealt with this as a neurosurgeon. Counseling usually helps. I think he's still working his way through the stages of grief.
Some of us were going to talk to him about trying to get his family back in this universe, but that opportunity is gone. The people capable of it are no longer with us. I never got a chance to mention it.
That's a good question to ask, about experimenting with the boundaries of all of this. It depends on who is doing the experimentation and what the experiments pertain to. Stark's latest attempt to study the Reality Stone ended up being a bad idea. There's still some room to test other boundaries. Let's just say, I'm not about to poke this universe and see how many times it takes until it pops.
That's what I'm going for, to pick up some shao mai. The food analogies did it.