Hey Skunki!
If you are still looking, please feel free to check out Secret Agenda - I am happy to send a discord link via bnet too!
In reply to your questions, you won’t really see a single server anymore. All OCE servers can play together now. So Nagrand through to Frostmourne are all together. I and Secret Agenda are based on Frostmourne as it was a bigger cluster compared to the others - but truly no stress on base realm anymore. Same for Alliance/Horde, all together now.
We are casual friendly, and have a few folks running pvp though majority do pve content - raids, delves and M+
Size wise, we are small to mid - 70 different accounts, with 8-10 active at any given time. As a few of us work from home so always around (team no life)