This is the outline for the contract that was signed:I, "SELLER", of BLANK Financial (the seller) am the owner of the property located in Pend Oreille County (assessors parcel number: BLANK).Said property is being sold via contract (the contract) to BLANK (the borrower) with a closing date that has yet to be determined.

@Jonathan KlemmThe property was vacant when the appraisal was done but I am not sure if this played a determining factor in the rejection because the appraiser noted that the property is grandfathered to continue its existing use but the exemption would be lost if the property remains vacant for 6 months or more.

How did you determine your rent income/occupancy rate? 

I am trying to learn how to determine a ballpark figure for how much my properties will appreciate over 10 or 20 years.

check your local laws on how to properly determine if a property has been abandoned by a tenant before you clear it out.  

Option 1: the 50/50 splitWe can just decide to ignore the differential in hours required by each of us to keep up our properties and can split all returns down the middleOption 2: billing the partnership for his laborWe can determine a reasonable market rate for his labor beyond a certain number of hours per month, and can bill the partnership for his time.

We need a lot more information to determine if you are or are not responsible

This is the outline for the contract that was signed:I, "SELLER", of BLANK Financial (the seller) am the owner of the property located in Pend Oreille County (assessors parcel number: BLANK).Said property is being sold via contract (the contract) to BLANK (the borrower) with a closing date that has yet to be determined.

Very difficult to determine pricing without seeing it. 

If the lease allows a new owner to terminate the lease with 90 days notice, it has to be determined what is the easier/cheaper option.