I agree with kdogprime's assessments. Concerning auto-cast, though, I can understand the possible issues. For an example of a game that does it right, though, look at StarCraft 2. Auto-cast only works for some abilities, and you can turn Auto-cast on and off by right-clicking on the ability.
To make it "easy", you could do that, make it able to be turned off and on, and when it's on, simply have the unit use the ability on the nearest valid target whenever it's available. If the player wants to choose better/more specific targets, they can turn Auto-cast off, problem solved.
I realize this isn't something that can be added quickly or easily, but it'd be nice to see it eventually.
Last edited by louthelou; 04/07/14 08:59 PM.