I know with a house hack it would cost less upfront to start but will guarantee a negative cashflow the first year.

From the folks I have talked to that have, they are their easiest tenants and guaranteed money. 

The 2nd reason to stay away from park owned homes, is that you lose the advantage of the MHP, which is essentially a trapped tenant, because they own their house, and they cannot move it, you have a guaranteed renter. 

That all depends on what promises or guarantees where made and what the contract says.

They provide a guarantee and come back out if I catch something in traps that are in locked spaces to find out how they got in and fix the problem.  

It's a simple form and a few Docs that they require  prior to the fee request and Paying the fee obviously doesn't guarantee that they will approve the deal. 

Similarly, it's almost guaranteed not to have a sewer connection which would need to be added as well. 

These tenants are so big that obviously you aren't going to get a personal guarantee out of them, but they're also such a safe bet that it's not seen as a big deal.In the smaller range of 3-5 year leases and small businesses, you don't see a lot of NNN, and you see more personal guarantees for the first term of the lease.

I can guarantee there is significant deferred maintenance on this property. 

Many LPs thanked their sponsors for good returns with millions of dollars in guaranteed fees, and tens of millions in carried interest.