I also have the most amazing handyman that ever existed that keeps my projects cruising forward on little things I can do myself, but don't have the time to over the week.You can do this!!!

Commercial is different as the business tenant can have lease capitalization and depreciation.As to requiring that no other financing lien exists, that is another predatory violation matter in financing.

One problem is, rather than replacing the rotted metal roof with another metal roof, the previous owner just boarded off the built-in gutters and put asphalt shingle roof on.

The "conventional" un-conventional method is to buy "subject to" the existing mortgage, flip, then satisfy the existing lien on your sale...

There may be a way to cash flow the property and take over the payments on the existing loan then the cost of the sale doesn't matter so much.

@Jean BolgerFannie Mae HomePath loans no longer exist, you are correct.

I would recommend you start by looking at who actually owns the land, what kind of easements exist, and whether their are any covenants that run with the land that address maintenance and or use of the land. 

Should I just offer to assume the mortgage and not give anything to the existing owner, or would it be better to offer them something so they are not losing all of their equity as well as ruining their credit?

This lack of financing is also having a severe impact both on those consumers wishing to purchase a manufactured home, and on the existing manufactured homeowners who find their homes diminishing in value because subsequent buyers cannot find the financing to buy existing homes that are for sale.

Check posts about seller financing and tired landlords.Throwing in a lump sum on existing loans doesn't effect cash flow immediately it shortens the time to the payoff and reduces interest expenses, that are deducted from income.