Thanks
Yeah the enemies are relatively easy since it's a PvP game (you'd be surprised though, some people suck lol). Once you get some players in there, the game gets pretty difficult. Also, there are bosses in Dungeon mode behind the doors in the Core you unlock with keys dropped by certain high level enemies.
The cursor for the client version is bugged right now, I'll have a fix soon. Until then, you can customize it in the menu.
The tier 2 classes only have one special ability on their RMB or Space depending, but they come with added abilities / buffs from their tier 1 predecessor. The t2 Priest's water splash heals allies that it his (including you) or damages enemies.