Then I verify employment and check rental history before having them pay for and complete online screening.

I installed a high SEER Mitsubishi 18,000 BTU heat pump / AC and then had an AC technician come out at the end to vacuum the lines and do the final electrical hookups and verify everything was good all for under $3k.

That's option 1If all you're wanting to do is sell the land that too might be considered  (verify me on this) to be a sec 121 eligible transaction by itself. 

I verified this with his bank statements which have big deposits and big withdrawals. 

Since we are unable to perform evictions, you really need to verify collections and the quality of the tenants in the properties you are underwriting.

If the tenant does not have credit to rent then needs a co-signer and they need to be verified and approved and I would explain that to the tenant and get the phone numbers of the co-signer and explain it to them as well. 

Of all the numbers I’m most uncertain about how to verify this.

The gentleman is in the Navy, the woman has a new Green Card and as such can not be verified for a credit or background check.

What other fees should I verify.

All of that vetting needs to be backed up and verified with in-person viewings to know what is accurate in your market.