Videogames exist in canon as they are shown playing some fighting games, so I wager RPG's exist as well, so they are just using familiar lingo.
Weiss actually strikes me as very unfamiliar with games, as she didn't even understand the card game they all played in canon. Others may be familiar with games, but not RPGs in particular. So yeah, I'd expect some, what do you mean by that going on at first. I'll be sure to add a bit to the Q&A that hits on that. And a joke about it to chapter 2.
As for the Q&A, I actually struggled with how to present it in a very Ruby and Yang way. Ended up rewriting it from scratch after getting an idea from my three year old though. The big thing is, while it looks like GW2 the game, it functions more like Guildwars in lore, that is, you see/read about people doing stuff you can't actually do in game. This will become more important as time goes on.
I did map each main cast member to a profession (class) as well as figure out what skills each uses, which was surprisingly easy. I want to avoid a naruto though, and not have people call them out during attacks, so I try to just describe what they do, though they can be referenced by name later, like Ruby did with a Nightfall, a type of greatsword attack.
