He is making $40K a year managing a gas station.

The local police station will offer a "landlord" course which basically runs over your responsibilities to your tenants as well as the community.

I'm stationed overseas and this tenant from hell stop paying her rent over 7 months ago.

I remember before an investor was burned using pay rents online.They had it where a tenant could pay and also could deposit money or wire money in.What happened is the tenant sent in 300 instead of the 600 owed into the landlord's account.The tenant argued in court that the landlord accepted partial payment and was going to work with them on an arrangement.The judge sided with the tenant.So the moral of the story if you are going to do this is only a set amount is allowed to be paid with no partials.If they try a partial it should reject the payment.Of course you can work out a payment with them IF YOU want to but you want to control that and not the tenant.On paying cash when I was 17 I was running low on cash.I went to the gas station at night and put about 11 in gas in the car.I had the money in coins quarters,dimes,nickels and pennies.It wasn't rolled.The gas station employee refused the money and I told him he had to take it.

Currently, he's stationed in Colorado Springs, CO.

Because they provide a better product than other gas stations (where I live anyway).  

No, they would temporarily just use a near by gas station, neighbors house, sink or just go behind the shed.

We also would just get on the bus downtown and ride it until it came back to the station lol.  

Similar to you owning a gas station and having an ATM guy come in and place a machine.  

They stay at the station so many days and then have so many days off.