For pvp I used keyclones maximizer to create 4 equally sized windows for my toons. Decent enough resolution on each to see what's going on but not ideal. I found keyclones pip feature to be too slow for PVP. I then just hit the corresponding focus button then click in the window I want to now control.

Click to move and interact with target help with gathering up a team and to have them face a target.
I'm not great with it at the moment. The way I have it setup it's too far away from my break follow, so they tend to run towards the target (sometimes you want that, but not always), when I just want to tap it so they turn then break follow so they stay where they are.

Disclaimer: Haven't tried multiboxing arena so any experience I have is from multiboxing BG's.