For those with major problems, did you do a factory reset? As has been said int he past, if you did not, you really should.
If you have doen a factory reset, have you identified what apps you have that might not be playing well with froyo? Those types of problems often come from a bad app running and running thus overheating and crashing stuff.
If I was you, I'd have them send you a new phone if the factory reset doesnt work.
I had all of those problems too.... the overheat problem had been getting worse and then today, all my apps started getting deleted and force closing in batches. I tried pulling the battery, going to Verizon store (no tech help at all and call dropped by 800 number while in store!!), and finally a factory reset. After the reset, I put only Angry Birds on there to play it for a bit and see about the overheating, which it did, again, within about 30 min.
I ordered a new one while at the store today since it was the only thing they would/could do for me and this phone is as good as useless at this point. I never rooted it, or abused this phone at all. Just tried to use it!
I am very hopeful that a new phone with 2.2 directly on it will solve my problems. Fingers crossed....