With most good tenants there is not much to "manage".How much is your principal pay down?

You can use a calculator online to find out the principal and interest payment then just add annual taxes and insurance quote into the payment.

Part of your monthly rent would go to principal reduction.  

We know being an landlord is a job, but if we hold it for long time, it can be a decent income.However, now we are thinking since the interest rate for our sfh is 6.375%, why not sell the townhouse and pay the principal of sfh?

Your mortgage is not only sucking interest, but also principal.

My experience so far has been positive.  4 investments starting ~ 9 months ago.  1 completed with principal returned, others are in progress. 

Yes, an entity can be appointed as attorney-in-fact for an individual.My concern about the above... an attorney-in-fact depositing the funds of the principal into their own account would be an obvious breach of fiduciary duty.

The drawback would be if you only make minimum payments, the balance will never decrease.

Even with a 5% down payment you are looking at a $2,494.00 a month principal and interest.

I've included an example below to help illustrate this.So different lenders have different rates (which do vary even for DSCR loans) but these are factors they all consider.See example below:DSCR < 1Principal + Interest = $1,700Taxes = $350, Insurance = $100, Association Dues = $50Total PITIA = $2200Rent = $2000DSCR = Rent/PITIA = 2000/2200 = 0.91Since the DSCR is 0.91, we know the expenses are greater than the income of the property.DSCR >1Principal + Interest = $1,500Taxes = $250, Insurance = $100, Association Dues = $25Total PITIA = $1875 Rent = $2300DSCR = Rent/PITIA = 2300/1875 = 1.23If a purchase, you also generally need reserves / savings to show you have 3-6 month payments of PITIA (principal / interest (mortgage payment), property taxes and insurance and HOA (if applicable).