It would be nice if you place system messages (i.e., loot, gold and exp gains, quest complete and new objective messages, badge completion, etc.) in the chat window. Sometimes after an intense battle, all you want to focus on is refilling health and these messages go by so fast. If they were copied to the chat window, we could check them anytime after the battle to remember.
For that matter, it would be nice if there were a combat message chat window where all combat and system messages were placed. There are some fights with very tall enemies (i.e., treemen and giants), where it is hard or impossible to see damage totals due to fixed camera angles during combat.
It would be nice in these cases to be able to see a log of how much damage was done during each round.
