Buying pre construction runs you this type of risk...not uncommon with Condos being delayed.  

It is not uncommon for them to insure themselves.

I was told by two realtors that the commissions for selling a mobile home like this would be in the $3k - $5k range depending on the brokerage, and that it is not uncommon for a mobile home to sit on the market for a long time.  

Multiple parcel numbers usually doesn't matter as it is not uncommon for a commercial property to sit on multiple tax parcels.  

Sellers generally like high down payments (skin in the game - 20% down is not uncommon) and high interest rates (6-15%) with balloon payments (at 1 year or 5 years or 10 years) or interest rate resets during the period (15 or 30 year amortization) of the loan. 

This situation is not uncommon in rural areas when the house is well off the road.

I wouldn't think it's super uncommon

Also its not uncommon that the tenant is responsible for all repairs or at least up to a certain amount.

If you check with your attorney (or any local law firm) they could tell you quickly as they generally make extensive use of trust accounts.Here taxes are billed to the owner, but can be paid by the property manager - it is not an uncommon practice.The same with utilities / fuel - the property manager often handles oil/gas/electricity billing where the costs are borne by the landlord.   

Personally I've never heard of a realtor doing something like that (wholesalers, yes this is not too uncommon) ... however, you could always put in an offer with the walkthrough contingency and then back out once you've seen the place.