However, you may also be constricted by DTI requirements, as DTI increases as you obtain more properties.

Most really successful investors I know were in the trades and/or real estate sales and are self educated and millionaires a few times over.

You will have to stabilize the turmoil that comes with drastic change, and changes you implement to increase efficiencies.

As responsible Real Estate Investors,  we want to educate them on their options:  Mortgage relief programs, loan modifications, forbearance, short sale, etc. 

As you bought it brand new, that is an important factor, but after 10 years, maintenance cost increases so that it is always good reduce the risk.

Many for-sale by owners aren't aware they are legally obligated to disclose.

Can my sister and I donate land my deceased parents received deeds through in tax sales? 

Jack Bosch and a lot of the land flipper guys who teach it like to have their students buying in the high deserts and remote areas of the Western US  or in FLA like le High Acres etc. this is were cheap land is and land that gets traded constantly at tax sales.. the play for most of them is really simple.buy at tax sale or with direct mail.. for a few grand  re-market them for more and sell on terms and collect monthly payments.. 

I can't work with them at all because they refuse to provide the original purchase and sale agreement.

If it is tied to the home, you have a few options:1) include electricity in the rent (down side with that is tenants may be less diligent with electricity use and increase the bill)2) have the tenant pay it and include a copy of the statement every 1-2 months to show that it is paid in full.3) have the bill in your name and send a copy to the tenant each month (or whatever the billing cycle is) and they can add the balance to their rent each month.