You kind of contradict yourself in the first sentence, lol. Is the UFC really in trouble if they are good financially? I know you say "they hit a wall", which could be true in certain aspects (like watered down cards, the superstars who are point-fighting, TRT scandal), but financially I think they are pretty stable and I don't see that changing even with all of the issues you've mentioned.
The points you bring up are all pretty valid in one way or another, however they don't spell out doom for the UFC in my opinion. More so, they are perhaps getting stagnant. I brought this up a while ago but the appeal seems to be declining a bit (to me at least). However that doesn't mean that the UFC is in trouble by any means. I mean, define "trouble".
Some of the points you bring up are reaching a bit.
-The UFC didn't have to milk Anderson Silva as the GOAT, he was the GOAT and the UFC actually got upset with Silva for a while for acting like a jackass. They were about to part ways with him after the Maia fight.
-Jon Jones being a diva really doesn't effect his drawing power at all so the UFC shouldn't really care about that. Floyd is a diva and many people probably watch him to lose... there's nothing wrong with being a diva and/or villain type character.
-Who cares if Cain isn't charismatic? He's still going to make the company a **** load of money anytime he enters the cage. Some fighters' games speak for them.