Hurdle 1) I purchased 4 rental homes between August of 2015 and November of 2015.

Have heard mention of sellers trying to force buyers to buy based off the claim of "unreasonable dissatisfaction of property condition due to insignificant repairs" or that the inspection wasn't performed by a qualified professional.     

However, a major hurdle was recently uncovered in that this property has back payments owed on a leasehold agreement ($7200).

That should be SOP, so it's not unreasonable.

This is the biggest hurdle for most people.Good luck!

This is a big deal so I'd appreciate your direction very much.Installment Land ContractSection 9"Buyer shall not make any major alteration or addition to the Property that would normally require a city/county permit without first obtaining permission of Seller, which permission shall not be unreasonably withheld or delayed. 

Maybe this hurdle is a blessing in disguise.  

Do they have money but are an overseas investor and will have many hurdles overcoming tax treaties and entity creation??

This may be your biggest hurdle in your ability to get a traditional loan.

Again, commercial lending is a different game, as there aren't the major regulatory hurdles that you have with residential/personal lending.