My friend wanted to lend me the money for my investment property at the same interest rate as Guidance and I would pay him a fixed rate monthly and we would both own the property until I pay it off. 

Until then just assume you’re financially better off with the rentals.

Power of attorney is not permitted, but I did have one lender who blessed off on a corporate resolution for a stateside entity member to have signing authority for the business.

Is it a good idea to start skip tracing or returning to an area on my day off and door knock or leave door hangers?

I have a DSCR product that would not have a waiting period off the market but would have a PPP and would only go up to 75% loan to value.

Maybe she just wants to make money off being my property manager in the future.

Answer: you would NOT be able to get a loan, period, the banks would shut down lending so fast your head would spin until Uncle Sam comes along and bails them out (again). 

Not sure of any residential lenders that can value the property off the income approach if that's what you're looking for, but you can still get appraisals that include it.

That sounds more like some document your friend typed up or downloaded off the internet.  

Borrower currently has an SBA second at 2.9% and does not want to pay that off.