Underground Buildings Exploits

[Vectorus]

I don't think this is an exploit, it's a good dynamic which forces you to use explosives - lasers are boringly the best at absolutely everything else. 

The power plant thing needs to be fixed though (if the plant is undamageable?), and the number of HQs should be limited to 2, and if there are 2 you should be allowed to demolish one while military buildings are still standing, thus moving the HQ location.