I inherited a tenant paying $500 a month. 

Your basis for inherited property is one of the following:1. 

Not sure if the tenants are paying their rent, hopefully they're not liquidating due to the moratorium and tenants not paying, because then I'd just be inheriting a mess.

These might appeal to owner where they can get some cash and then a installment plan that gets them cash they werent getting from the tenant vs before when the tenant was actually paying rent.Proposed Offer options ( i want to present all 3):100k cash offer-160k offer- 20k down, 140k seller financed at 4% interest ($668 monthly payment) 30 year amortized, 10 year-term with balloon, 3 month delayed payment for rehab180k offer- 0k down, 180k seller financed at 4% interest ($859 monthly payment) 30 year amortized, 10 year-term with ballon, 3 month delayed payment (I will pay all closing costs including realtor commission 5% since he is the middleman)(or I can write the owner direct and bypass the agent since the listing is now expired/ delisted.)I'm expecting to inherit the tenant and allow him to live there through the end of the spring and try to begin eviction in the summer.

This type of system would minimize or at least lessen that issue.I am a big fan of the variable speed pump so I think that's a good choice you made! 

7) The seller has not communicated a sale price or provided a profit/loss statement to date.8) Our strategy would be primarily to buy and hold, possibly flip a few.Bottom line: It's an opportunity to inherit multiple properties at low/no money down.  

Next week we will be meeting with the out-of-state heirs on a house. Since the house is in our neighborhood, we know it’s been vacant for a few years and the exterior shows some signs of deferred maintenance i.e. fall...

I would check into building codes and fire codes that are applicable.Check with your attorney to see if renting to the Elderly tenant directly and letting her make sepparate arrangements for care with the other tenant would lessen your liability.

I inherited these tenants with the apartment.

Its a struggle I have had to deal with when purchasing inherited tenants as well.