Hi, and welcome to the board!
Starting somewhat off-topic, there is an Official Introduction Thread
if you would like to introduce yourself fully (but please don't feel pressured to do so).
Now, back on-topic, which I think is something new for us after so many years of discussion (not all of it totally original!). I happened to watch both movies very recently, and I always notice the difference between Winston's attitude in the two, from "No offence, but I'm getting my own lawyer" (apologies if I've slightly misquoted) to the relationship that the younger audience has come to expect from RGB. Here, I may be going over old ground a bit, but it's worth reiterating that RGB gave Winston the development he needed, as a cartoon protagonist, and this assuredly influenced his role in GB2. This is (as everyone knows, but I'll point it out anyway) the "real" and therefore the dry, boring explanation for how his relationships within the group developed.
To speculate about what happens off-screen within the fictional world, as your original message proposes, is much more fun. It seems to make sense that through the climax of GB1 - with all four Ghostbusters ultimately defeating Gozer through extraordinary risk to themselves - that bond between them is forged and their closeness follows on quite naturally from this. What's missing (and may have fanfic potential? I don't know) are the moments between washing off all the marshmallow and the RGB status quo being established. Of course, there is
an episode with flashbacks taking up where GB1 left off (in fact it's a bonus feature on my movie DVD, but I haven't watched it in forever); this is not my area of expertise, but it may lead to further discussion from someone who knows all about it... (No pressure, Fritz!
was the best-written show, because it wasn't just about the ghostbusting, it was about the characters.' - Rino RomanoEGB Fan's EGB Fans
EGB Fan on FFN