Hey friend.
I haven’t been on many of these threads recently because of how busy I’ve been, but I can say that Hand of Algalon (is that right? Ulduar boss.) would probably be the first go-to. They are light-medium RP and they focus on the other aspects moreso. That said, they don’t grief, and the leadership keeps everything tidy.
Not many guilds shoot out at me immediately, but I do suggest taking a look at the Horde Guild Directory. It’s a much better search than doing the in-game outdated system.
Hope this all helps!