[dev1022] Instead of Auto Attack how about Command stack?
Basically you can select 5 commands in a row to be executed when the action gauge reaches the command. To delete the command input just press cancel.
This way you can keep the current system without much change but allow people the ability to chat and engage in battle. Best of both worlds.
Simply adding Auto-Attack isn't going to allow you to chat. The battle system is still ability heavy and still will require you to input alot of commands. TP builds very quickly and alot of abilities don't have thos long 3-5 minute cooldowns like FFXI.