I want to increase the rent to $1500 which is still under market and offer them free air conditioner if they sign it within 10 days.

If you do have a pet free unit though it is my understanding that you have the right to have it returned in the same condition so it seems fair that they are responsible for carpet cleaning and I would go for air duct as well. 

I "third" what Ryan and Jordan said about Bastrop being the most desirable of the three cities you mentioned... if that's even a thing? 

@Robert Jordan I think you’ll find maximizing occupancy isn’t always a great idea.

@Jordan DeeneyEspecially with what you did removing a wall I would have gotten a permit, some cities you need architectural done some not you can just hand sketch.

I would also look at a duplex , triplex or 4 plex so you can Air BnB if allowed or have the other tenants help pay the mortgage while building equity.

Have you been changing the a/c air filters?

Buy a couple beach front properties (Panama City) and Air bnb?

@Jordan Moorhead, please send along that name, and I'll follow up. 

We live in the suburbs of Portland Oregon and air conditioning is more of a bonus not expected here, especially in older homes.