After playing little Beta version I noticed that if one uses Vikings and orders them to attack, it is possible to click on a ground unit while being in air mode and target air when i ground mode. They will howver not attack but instead dispaly a message. However how about making them auto transform istead?.
but what about the misclicks that can happen....i may want to attack some mutas but there might be lings running under them....one wrong click...i guess u got the point
Yes, what Spardas said as well as the fact that the hotkey is just "e" and "d" which is really simple. Think of it as "e" is up since it's above "d" and vice versa.