More rock will give me more room for coral! Especially SPS closer to the light if I decide to do that, and more room for bacteria to break down fish waste.
I don't think water quality will be an issue unless one adds a large fish not meant for small tanks.. or a messy fish. The issue will be crowding the fish and stressing him out. Like, I wouldn't put a clownfish in here for sure. But a clown goby, firefish, watchman goby, etc all meant for 10 gallons would probably be fine.
The stray voltage thing isn't as easy for me lol. I think the outlets in my house are not grounded. I'm going to be checking them soon.
Nice to know you got an evolve 4, too! Did you have problems with it like I did initially?