I have two things. One is simple. Combine some of these "results" screens after you do something. No reason I should have to tap 5 times before I can thank someone after a battle. Clean that shit up. Same for entering a passphrase in a private match. Once you click on private match the first thing you should be presented with is a text box that you can immediately type in.
The second and most important suggestion is to prevent players from conceding right before you get your last point. Make conceding on your opponent's turn have a 5 second countdown allowing the opponent to finish up any game-winning moves. Leave an exception to this if your opponent's turn has taken more than 10-15 seconds or you've been presented with a choice you have to make (ie Sabrina etc.).