Oh I doubt you'll have to worry about the game proper being "friendly." We're cordial here on the forums where we get to interact and get a chance to know the other members. But being that the core population is quite invested in their faction, combine that with deep lore to draw a true sense of animosity not for the players themselves, but the faction they play as, once they become faceless combatants I fully expect there to be a true sense of conflict on the field. I mean, what Chaos player doesn't want to finally pay the wolves back for Prospero in kind? What Ork fan isn't tired of their faction being the punching bag for the heroes of the Black Library?
I'm pretty sure the community's going to devolve into being similar to Planetside 2's where we cry for the devs to nerf the thing that killed our character last.
This is technically supposed to be a B2P game, is it not? I think BI is selling themselves a little short. If buying the game or spending enough on micropayments gives you full game access, I don't see why a large majority of players wouldn't.
Well, if the free part of the game is fun enough, there won't be a reason to expand for most players, unless of course you are truly hooked. I'd never buy Planetside 2 for this very reason. "Oh. More guns that shoot, what, bullets? They have different stats? And colours?... Yeah no." Anyway it's still players, and players are good. Most of those people will have a pretty boosted Ork character at that point, too, so some might just stick with us. We are a lovely bunch. Genocides not included.