Your tenant has trained you well.When you have an illegal tenant in a unit, you can send the resident a lease violation notice stating that the person needs to be on the lease, and they can pay the application fee for the background check.  

I get this isn't ideal but it's reality, you have massive PM issues, transactional issues, you need a few professionals immediately. 

Make sure you track these amounts, so you know how much to transfer back to your personal account when the business acccount has the funds.Do your best NOT to mix business & personal transactions.

It needs to be written down so you can objectively look at each potential tenant and defend yourself if you are ever accused of bias or discrimination (the illegal kind).

You'd just put whatever shows that you're serious and capable of closing on transactions: you have educated yourself, you have objectives, you have (access to) money and you're an action taker.

They approve loans and make money available for sale transactions within 1-2 weeks especially if the buyer is pre-approved.

If you're unfamiliar with the reasoning behind non-recourse loans in this case, it's because of the prohibited transaction rules.

If you are doing much of anything else you are effectively brokering the sale of real property which is regulated in the US, i.e. you need a real estate license.As far as a real estate transaction goes, in brief:  get an offer accepted, enter and finish attorney review, now the property is "under contract" to sell, complete any due diligenence (e.g. inspections), get to closing...Since you are selling the Right to Purchase, you need to have a contract first. 

@Ron Lamb being a former employee of Wells Fargo I would not recommend them for any type of investment property transaction. 

You will need to start with the attorney to make sure you have all the initial paperwork necessary for the transaction.