Hussar
Legend
Not as such. Previous editions allowed for more mutable combat roles, and perhaps role was not necessarily merely a combat consideration. As far as combat goes, in OD&D (and AD&D, I would venture, maybe even in 3.XE, though perhaps less so), a character might be stepping into combat for a few rounds then stepping back to support, possibly administering healing, by potion or spell, then pulling out a bow/sling/x-bow and helping in that manner. Neverthless, the thread's real question might be moot for you, since the question that I'm asking as the OP is regarding how tightly "role" is tied to combat. Perhaps you see no sense of "role" in RPGs outside of combat?
Hang on a second. This example doesn't actually work. Everything you just outlined is pretty heavily punished by the rules in any edition.
1. Fighter steps out of combat - Pre-3e, every creature in melee combat with that character gets a free shot on him. In 3e, he might be able to disengage without taking an AOO, but, he's not going too far.
2. Heals. Ok, fair enough.
3. Pulls out a ranged weapon. Pre-AD&D - cannot fire into melee at all. AD&D - 50% chance of hitting allies when firing into melee, 3e, takes a -4 for firing into melee, possibly with an additional -4 because of cover (which his own allies might provide).
So, no, what you're talking about doesn't really happen very often. It might once in a while, presuming that the bad guys can't just move forward with the fighter and keep him in melee, but, it's a pretty rare corner case example you've brought up.
Certainly not a very good example of how combat roles could change in combat.
And, you still didn't answer my question - how are any of your other examples actually tied to class. Since all the things you listed exist in every edition, and none of them are tied to class, how does combat role have any impact?