I 10000000% guarantee if I sent the dude a generic letter to the mailing office saying “I want your property” it would have been trashed. 

I would like to just make up a generic name for the website where the tenant portal will be.

Sell some houses here and there to supplement your income.

Its pretty rural so i'm not sure that would work very well but at the worst we would just be adding another bedroom/bathroom. should we just flip and try to find a new deal or two or should we hold onto this house and try and supplement the mortgage with house-hacking income?  

The whole point of investment properties is to PREVENT this type of situation, by having supplemental income.

IUL's and Fixed Indexed Annuities are great resources to help supplement your portfolio and help with optimizing taxable events. 

Maybe you could each work so part time easy job to supplement your life style for a while.

Many investors use either web-based generic cost seg services that do not actually inspect your property or some kitchen table estimates. 

During the height of the worst real estate recession in the last 100 years, large multifamily had the lower mortgage delinquency rate out of all real estate subclasses (0.4% MF vs. 4.0% SFH) so yes, the syndication model (which is just a generic term for raising investor capital and is nothing new) absolutely was tested and passed with flying colors.

We can give you some generic answers, but you really need to speak with a lender to see what YOU will qualify for.