The only server I can think of that may meet your requirements that I've played on... would be TrinityRO. It has a HR server 10k/10k/100 and a MR server 75/75/25 (20 for cards).
The MR has a decent community and is PK. The HR I'm not too sure about, but I think it's currently more populated than the MR. Class balance.. well probably as balanced as most servers out there.
The only real problem I had there is a group who wouldn't leave my guild alone, harassing us, etc, so we left. Another problem was the Admin. I think he's trying, but he does tend to make many mistakes and is almost impossible to get ahold of. Max lvl for both is 99/70.
(If you want anymore info please let me know, I can also give you the site link if you need it.)
Well.... I'm somewhat content with my new server, except that I'm getting a bit bored, so I'll see if someone can come up with something of my specifications XD
Rates: Anywhere from 40-90/40-90/20-50
WoE: Two times a week... >.>... I'd specify times but most server times are different.
Population: Somewhat populated, anywhere from 50-400. (Big crowded servers scare me >: )
Class Balance: >.>.... Is there really such a thing?
Max Lvl: 99/70 for basic and advanced.
GM's: MUST BE CARING, helpful, and nice...
Ad on's: Resetter is fine, healer is fine, stylist is a must have, gunslinger/ninja would be nice, customs are okay-but they can't be overpowering.
XD Haha, I feel picky. If anyone finds something promising let me know =p I've yet to find anything fit to my needs XD