This is one of the ways we all learn is by asking questions.The 6 month seasoning period is very common.

A general valuation formula many in the industry use is: # of economically occupied lots * monthly lot rent * 70% (assuming 30% of income goes to expenses, common for parks on city utilities) * 12 (months in a year) / desired cap rateFor this park at a 10 CAP (many parts go for lower cap rates now, but small parks might still go for a 10 CAP), that makes: 21*298*.7*12/.10 = $526K . 

Is it possible to also write off the other common deductions (PMI, interest, depreciation) while living here? 

Some people like the 1 LLC per property since its common to name the LLC the street address for the property. 

506(b) is quite common if you have a preexisting relationship with investors and do not need or want to publicly advertise. $150-250k is a pretty small raise for a syndication, though.

The most common portfolio style loan in Texas is a 20 year adjustable rate loan.

Is it common to just put the rates up to what you wish on buying the property.

Does each family member own an undivided interest as tenants-in-common in the property or is it owned inside of an LLC or other entity? 

In regards to inflation in your commercial leases, there is a clause that is commonly used called "Indexed Escalation."

Does anyone here know what are the common problems that a host has to expect in doing Airbnb hosting?