After getting under contract, it was brought to our attention after requesting copies of the leases that the current owner did not put the tenants under a physical contract, nor did he collect security deposits.

In doing so I have been cursed at, referred to as a slumlord, physically threatened and assaulted.

The skip trace software is amazing because the more data you can put in—the tax mailing address, the actual physical mailing address, the person's name, the cities they're in—it’ll start pulling all their known telephone numbers, email addresses and mailing addresses.

It is run by the MN Secretary of State and allows police officers, government officials, victims of domestic violence, etc to hide their physical address. 

Not even an animal for a physical disability.I don't think you could exceed occupancy limits, but I'm assuming you're talking about the opposite. 

Be careful though because sometimes the owners mailing address may not match their physical address so pay close attention because that’s probably a rental.

From the way it is worded I always thought it was only referring to physical damages.

The owner is asking for 10K down and 900/month for 2 years, at which point I could exercise the option and purchase the property for 125K.

If the buyer says a letter is good enough and that an email is not good enough, why don't you simply go back to the HOA and get a physical letter from them?

The tenant doesn't own anything until the option is exercised and they actually buy the property.Owner financing is the owner acting as the bank with a promissory note with the terms of payment (principal amount, interest rate, number of months).