To address the difference between Light and Heavy attack, choosing one or the other could just make that your new auto-attack until you select another.

I think it's been argued by many people that an auto-attack feature is necessary. It's difficult to throw away a system you worked hard on, but in the end, you want players to be comfortable. We would rather talk to one another and worry about buffing our weaponskills than pressing one button over and over and not being able to socialize.