Making those extra payments doesn't lower your payments unless you recast the loan (assuming your lender is fine with it) or refi.With $20K I would stay put and learn.

Because if you have to even ask this question, you just may not be cut out for this business.....and that's fine.

PS when you go into the health department ( or whoever controls on site sewage) you may find out also that your individual systems and tanks are fine.. but you want to know for sure before you spend any money.

I might tell you "fine, I'll buy it, you manage it, and I'll pay you the PM's fee." 

For me I use; 2nd lien on target property or cross collateral property deed of trustJV agreementPromissory NotePersonal GuaranteeMay be over kill, but I am fine with it.Also if you ever foreclose on a property that has enough equity to cover your loan I assume the 1st lien gets paid and then the rest would go to the 2nd position or is that not correct?

You know all and your strategy is better than everyone else's.I'm doing perfectly fine and I'm comfortable and that's all I'm going to say.

for me I always tell folks right off the bat its 40 to 50% of your rent on a 1400 and under monthly rent will go to  expenses PM etc etc.. if you do better fine.. but to think that 30% or less is going to work it could happen but probably wont.. and then you have disappointment.

Split 50/50 is fine. but The guy interviewed me was very pushy to get me on board.

No different than someone trying to daisy chain or work around a wholesale contract and investors here think that is immoral or unethical, but doing it to a agent is just fine.

If the existing system is already on its way out the door then removing it may not affect the tenants that much as they are used to its unreliability and you may be fine.