Why not then use the same system nearly all the other MMO's do regarding PvP and casters... each hit increases the cast time slightly, not interrupt all cast timers all the time. The only skills I have that do not have a cast time are things like regen, benediction, surecast (which would allow for a single cast time spell to be fired off... if it works properly), Aero I ...

My 2 matches which I just jumped on to look at the mode was ...

Buff, start, pling pling pling why pling cant pling I pling cast pling anything pling... no matter where I ran.
The second match was more of the same...swarmed the healer, and got told to go commit suicide in real life by one of the players.

I didnt even get a look at the bloody arena I was targeted so fast... are the stuff in the arena to LoS enemies ? Platforms, stairs ? I dont know... didnt see.
Not fun wont bother with it again.