These things are available every 30 seconds? They expect us to go back and click this stuff every 30 seconds? Seems like it would just get in the way for a pointless necessity...

No auto cast for Mules or Obilisk (new name for Dark Pylons), or for the Queens ability to spawn Larva for that matter. The thing is, these abilities can be used optionally and using the ability costs energy that you could also use for Scanner Sweep or the extra supplies on the Command Center for example or for the Obilisk loading your units with energie. So using this ability to get extra ressources should still be a choice.

Also, as already mentioned, this is an option that advanced players can use to really get ahead in the game, it is not necessary to enjoy the game as a beginner. Still when you have a couple of expansions, you can really see that you got to pick up on your game to really fully take advantage of these features, especially if you have battles or harassment going on at the same time.

At first thought that idea seems quite powerful to me.