I think it would be nice to simply let the computer play while you watch, with the ability to shut it off at any time and reassume control. The computer would almost invariably play worse than the human player, but if your squad has the deck stacked well enough in your favor you could get it done with sufficiently low casualties. It would really help remove some of the slog of running too many missions, and may also lead to equipment strategies related to getting the AI to do a better job when playing for you. For example never put blaster bombs into the hands of the AI because as you've probably seen the aliens do, they kill themselves more often than they kill their opponents.
One thing you'd definitely not be accused of doing is cheating, as even at its best, the AI is brazenly stupid.