@Wolfshadw
ARC is technically what was Perfect World Europe, AFAIK. The client pretty much works like Blizzard's or, to a degree, like Steam's. One account for all games, associate games to account, friend management, download, install and play.
As for RPGs, I'd give a try to Vindictus, TERA or Neverwinter, but they kinda require the nice rig to play, especially the former one. Their "cash shops" are also slightly on the game-breaking side (especially the former, *cough*Nexon*cough*), but they're not mandatory to let you achieve a decent level.
Should you not meet the requirements, Path of Exile, is quite fun and addicting, while not requiring too much power from your computer; also, you could almost say it's Diablo 2.5 for free, and last time I checked the cash shop wasn't game-breaking either. Definitely worth a try
Blacklight and Alliance of Valiant Arms (also known as A.V.A.) make up for nice free FPSs, but the cash shop there is beyond broken...get a weapon from there and, provided you got minimal aiming skills, you win. Pretty much what happens with any F2P FPS anyway, reason why I'm not continuing on examples with them.
Otherwise, you could wait for a western release of Blade and Soul, like almost a quarter of its population...
That, or play in eastern servers with unimaginable lag