Ask the seller about the condition; has anything been updated, age of roof, hvac, electrical, plumbing, etc.

The electrical and septic (if it is in good condition) are a good selling point.If I were the buyer and really wanted that lot, the trailer and barn would not be a problem.

Cash-flow is hard to find with the current market conditions.

We were just approved for financing, but a condition is that the cosigner must be on both the mortgage and the property title.Our intent is to only keep them on for a few years, then refinance and remove them from title and loan.

Car washes and laundromats can be nice part time businesses, but all depends on numbers and condition.

It closed much tighter after that but still wasn't air tight. jalousie windows by definition will never be air tight unfortunately but they should be tight enough to prevent insects from entering. depending on the condition of yours maybe swap them out for regular windows if the energy efficiency is what you're looking for. mine was in a condo so i had to keep with the same window style. 

Typically, any existing park is grandfathered in with a conditional use permit that will allow the operation of a park as long as the property's use as a MHP continues uninterrupted.

@Roger Devore, without knowing the condition, I would say a lot of your assumptions could be aggressive.  

Ideally I would like the property to be in good standing condition and am OK if it's in need of cosmetic updates.

If it is part of the property they occupy as a condition of their lease, I'd almost guarantee the answer is no.