Ditch energy for a ton of hp and good heat stats. I wouldn’t recommend using auto-play, but if you do make sure you don’t equip anything you don’t want the AI to use. (For example: It uses Repulsor constantly, for no reason. So don’t take it with you.)
That being said, Mission 6 on Overlord’s Den is easy to auto-play on insane with just about any mech, and gives like 85-90% of the rewards for 75% of the price. So I’d recommend using it instead, and farming Ramboy for fortune boxes.