Hey BC, these things are really tough to decide. I don't feel there is a clear solution for you.. just a lot of murking around trying to figure out what course is best. These injuries are usually like this.
I would say that due to your past of no pain, even with OCD, I wouldn't immediately panic and rush into a surgery. Remember that with surgery comes risk. You know what you have now. You have no guarantee of what you will have after surgery.
About PT:
I also wouldn't count on PT too much. In my experience PT are extremely limited in what they can do for OCD injuries. What are they supposed to do, when the problem is bone and cartilage related? They have no solution except more PT, because that's the only thing they offer.
About Recovery:
What happened to your shoulder? If the shoulder isn't serious I'd get that healed first so at least you can use crutches at some point. Recovery is tedious but it is not complex. Enlist the help of others.. get crutches, wheelchair, etc. Someone to drive you around if need be and buy groceries etc. Recovery is something you can manage and which is in your control, so I would worry the least about that part..
About "85% better":
You hear this statistic thrown out a lot but it is largely meaningless. How is "better" defined? No one knows, and no one bothers to inquire deeper because I doubt the studies are actually there. From my experience I was not one of the "85%", and I've heard more horror stories from others which leads me to seriously distrust doctors whenever they parrot this number around.
Is the little improvement worth the risk, money, and recovery?
This is tough to answer. Depends on what you're willing to live with.. what kind of risk you will take.. how bad your ankle is now. I would forget about ever playing sports again. It sounds very harsh but I wish someone had forced me to let go earlier. The scar cartilage formed from MF simply isn't very strong, so even if you can run at first, the cartilage is not going to last very long. In the best case I'd give it a few years at most if you play sports.
If you want to know my anecdotal experience I'll add that in another reply. I tried to be objective in this reply so as not to color it with my personal bias too much.