I know this is a joke but it's a comic community so if I can't "um akshuwally" here then where can I?
Wolverine's healing factor does actually heal trauma. By blocking it out to the point Logan forgets it ever happened at all. It's part of why he loses his memory so often.
I think so, got this screenshot from early in Claremont's Uncanny run, which started in 1975. I recently read a comic from later in that run which was from mid 1981, and I feel like that one was at least 18 issues after the one I got this from.
The art does look more like Byrne than Cockrum, but Wolverine also had his brown costume later in Byrne's run in the '80s, so if I had to place a bet, I would say '70s.
Byrne began drawing X-men in 1977 (Uncanny X-men #108), and the brown suit was introduced in #139 (nov 1980) so 70s is definitely your best bet here. (This is 100% a Byrne panel.)
Edit: I had a hunch and found the issue, it's from #125 september 1979, page 6 ("The perils of the Danger Room!").