Interesting.

I was trying to figure out how xp was earned by using Healing. This is kind of a weird mechanic because it's not based on actually using the skill. The skill just sets a timer and you then blaze through as many mobs as possible before resetting the timer.

Does First Aid xp come in addition to your hotbar skills or instead of certain skills? I would assume the former.

I like the idea of requiring combat in order to heal, but I think the formula should be reversed; xp should be based off of your heal on a combat timer rather than kills during the heal timer. Total amount healed should be the determining factor for how your skill is increased so as to not allow people to use a bad kit or spam heals at full health during combat timer. That way, overheals don't count to the overall healing skill up.

Haven't done group combat yet. If you haven't attacked the mob and your teammate has, does that put you in combat? I think it would be important to seeing how healing others is affected during battle.