Well, to clarify:
1. I tend to forget refreshing groundings when there are 4 dps plowing me into the ground. Putting them in buttons I am certain to press with regular intervals is a neat way to help me not forget them.
2. My reasoning for never using TS x4, is that.. well.. if the team has such low hitpoints that you are able to AOE them down with the weak damage of your Nova+TS, then you shouldn't have a problem killing them with TS rotation and single target nukes. TS x4 can be a fun and gimmicky maneuver, but for arena it's a BIG reduction in survivability for the next 40 seconds.

Edit: Often in 5v5 I find myself losing 5 vs 3, after killing 2 of them. Usually there tends to be DK + Pala + Healer left, and they can just mow me down if I don't have cooldowns and mana up.