Who is Davis, the nerdy guy? (San Junipero)

Is Davis the nerdy guy or did you mean Wes? It appears Wes and Kelly had a fling and he still has feelings for her. I don't think there is any significance to his character beyond that. He did push Yorkie to search for Kelly in different decades. If you meant the nerdy guy I think he is just meant as a comic relief character. He pops up often and clearly has a crush on Yorkie not realizing she is gay. I don't think he had any importance with Kelly. Seemed like they were passing acquaintances at most since we did see them playing the dance game together.

I don't think the nerdy guy knows Kelly. I think he just hits on Yorkie because she looks like his type (nerdy).

As for Wes, I guess he and Kelly had a thing. She's done with him but he still has feelings.

I don't believe it's "not quite heaven" for some people.

Remember, San Junipero is basically about Internet addiction. San Junipero, the setting, is just one of many scenarios you can jack into. But there are two kinds of people. Yorkie asks Kelly how many are dead, and this seems like it's from out of nowhere, because we haven't really got to the twist yet. It's a weird episode and we're still guessing. She puts the figure at around 80%, I believe. So the other 20% (including them) are visitors. They can only log in for a set amount of time, and at midnight in the game world, their time is up. The ones who are "dead" are residents and they have no limits, because as you later learn, these people have been downloaded into some cylindrical computer thing that is permanently installed in the server (credits scene).

I'm guessing Davis and Wes are "dead" and are basically hitting on the "fresh meat" (those who haven't died yet) because they're tired of the residents. Kind of like how locals will prefer to pick up visitors/tourists at a bar as opposed to, you know, their neighbors.

A lot of this is assumption, though. Pretty much anything beyond what we're told.

- Dark Reality