Interesting conversation.
First of all it is correct that he did in fact get a new mask in part 8 since Tina spit his mask with her jean grey powers in part 7. This would have been the mask that tommy gave him in part 6 apart from the one that he did wear and died in from part 4.
Tommy did in fact kill him in part 4 also cutting his mask off in the process.
Man oh man do i love some Jason conversation.
And yup is me from last Halloween in image
Jason does gain a regenative healing factor after part 6, in that film if you didnt notice, his wounds from rotting away begin to disappear gradually, in FvJ, at the end when freddy gauges his eyes out when jason drags freddy underwater, the next day or when ever it is jasons eyes are back when he's carrying freddys head, so yes he does have a healing factor.
His body is a dead corpse, but his actual brain is not, he still retains memories. His brain apparently got kickstarted from from the Bolt