Arena opponent selection - if I hit regenerate, show me 3 new opponents. Often it only changes 1 or two of the opponents. Of course eventually it would start recycling, but if give me 3 new opponents with each refresh, would see my options quicker. (Or let me mark which one to keep on the list, then show me new ones in the other slots so I can narrow down who I want to fight.)
Make it so one can reasonably tell from opponent selection screen (arena/gw) how tough this opponent really is. Make all the hidden extras apparent.
Add symbol to indicate which opponents have zetas.
Add some indicator of how heavily modded these opponents are. (e.g. portion of their power score that comes from mods (i.e. what power is - what would be if had no mods) might be a crude indicator)
I shouldn't have to click through each character and their stat sheet just to get a general idea of how tough they are.
Or, in arena, have it show average of how I have fared in the past against this opponent. (I often see same people in arena). My results will change as they or I use different teams, but an average of the last few encounters would help me recall who had that really heavily modded team which was so much harder than typical of that composition.
Fix the censor in the in-game chat.
Currently it reminds me of a game they play on "I'm sorry, I haven't a clue," in the game they play a popular song, and panelists bleep out words to make an innocuous song sound really filthy. In the same manner, since the in-game censor censors letter sequences that occur inside words, it tries to make normal words like cumulative seem naughty.
In addition to the filter for squad editor idea, suggested above, add filter to character selection screen when preparing for a battle. As we get more and more characters, it gets really cumbersome to scroll through them all to find a particular one. If I could ask to just see my favorites, or if I know character I want is ewok (burried someplace in my list).