Being as fiscally responsible as you are is an enormous factor in staying afloat during those difficult times.  

hi marcus. yes, filters need to be changed often. in fact, i recommend at least once a month, depending on the location of your furnace and cold air return system. that being said, here is my experience and expertise. ( i just competed getting my certification in furnace repair). the purpose of the cold air and fan are to circulate the hot air to the area where heat is needed. but the purpose is also to cool the heat exchanger in the furnace as well. the heat exchanger is a sealed system of pipes that the heat created by the burners heats up. the air from the fan/ cold air return blows passed the heat exchanger to circulate the heat to other areas and to cool the heat exchanger. if the filter is clogged, no air gets past the heat exchanger and consequently, the heat exchanger will overheat and get damaged. i have personally seem the heat exchanger with massive holes in it due entirely to a clogged filter. it is highly unlikely that your heat exchanger inside is full of dirt, but the fan and area around the heat exchanger could be filthy

Massive water damage everywhere. 

In all likelyhood, unless there is a personal or fiscal need to sell he's probably not going to be interested in selling.

Monday, I have a meeting with a local attorney(did not know finding an attorney alone who is willing to close creative financing was going to be MASSIVE WORK) and due to the less than limited amount of attorneys who are not intimidated with this allows me to go to them with a bit more knowledge in knowing what needs to happen. 

Wholesalers do have to put in massive amounts of work and effort though, to find those deals.

Not sure I would be investing in RE there, well... maybe farm land in India and stock in Deere to take advantage of the growing cane market / technology (assuming the need for massive sugar demand to produce building materials).To the question, for me... hands down Option B. 

Goal would be to create a win-win of making tenants aware of solid fiscal practices (w/o being condescending) for a better life for themselves and indirectly also hopefully helping them plan to have money at the beginning of the month for us. 

I know you want to help your Dad, but 50% of profits for the use of cash is the equivalent of a massive interest rate.

The only way that thing wins if its in a market with massive appreciation, which isn't going to be the case in rural area.