I wanted to know the consequences of leaving your Case open.... (Only one side...) I wanted to install lights inside my pc, but when its closed, its not very useful!
You can leave your case open, Ive done that heaps for ages. Theres bad thing though like dust and if it's left on and you do something else, and theres young kids around they could stick there hand in there. But that's common knowledge the lights are in there so you can see, not really for looks.
If you're going to have your case open 24/7 then I would suggest a room fan as well. Not only will you get to see your lights and hardware, but you can lower your temperatures even more. I've had my side panel off for a few weeks now after i bought this oscilating tower room fan and it does wonders for my room temperature and my CPU.