The arena matchmaking is more or less balanced of your arena rank even if you are waiting in a q if you are higher rank you are unlikely to meet weaker players unless there is absolutely noone else in the q. That tends to work pretty well overall.

This will most likely be resolved once servers are merged .

Yes arena is just not very interesting at the moment. We dont have any of the arena features like China for examples where they get trial ninja for a week in arena based on their rank to try out etc.I personally hate doing arena and dont even finish the 3 daily for quest as long as i got my arena points.