Is there anyway to get rent money back without having signed papers?

No, you lived there so you can't get the rent back. Your only remedy is to move.

All your rent pays for is the ability for you to have a roof over your head. He has to be compliant with certain laws, but nothing you mentioned is illegal or makes him liable for paying you back your rent. Paying rent does not ensure that you live in a house that is maintained. Paying rent does not ensure that you have the luxury of a working air conditioner. Paying rent does not ensure a maticulous backyard either. And as far as inspections go, he has a certain timeframe to fix the things to be in compliance. And that still doesn't mean he has to return any of your rent.

Btw, if you haven't signed a lease, you're free to leave whenever you want as long as your rent is paid. So, if it's June now, just move out and don't pay July's rent. Problem solved. If you can't afford to move out, that sucks for you.

There is no way that you can ever ever ever get back rent you've already paid in your situation. At the very best, you could petition the court to set up an escrow account to put your rent payments into so that he doesn't get any more of your money until he makes repairs that bring him back up to code. However, if he does fix them, that money goes to him. If he doesn't fix them, then you get to keep the money in escrow. But there is NO WAY you're getting back any rent you've ALREADY paid.

"I feel like he isn't using it like he is supposed to." - There is nothing that states how he is suppose to use rent money. It is income for him, and he can use it as he wants, just as you can use the money you make from your employer any way you want.

So why don't you move if it's so bad there? Yes, you probably will pay more for rent than you are here, but you get to pick the place you live and probably will have a better quality of life in your own place. Most landlords are not like this, so chances are good that you will live in a place where things work.

Get money back, no. But you can put future payments in escrow not pay him any additional rent until he brings the place up to code.

P.S. It doesn't matter what he spends his money on. The only thing that matters is that you are paying rent and he isn't providing a livable apartment.

No, you cannot "get" money back if you are in an unsubstantiated agreement. Your bad. Back yourself up on paper next time.

You can try illicit means (ie: robbing) but that is not wise and could get you beaten up or worse.

However, he can't really kick you out, either, if that's where you stay and he can't prove you are a lessor. Obviously, you can't hang in such a situation very long, but if he tries to kick you out, call the cops.