Get them on a lease and make them put a deposit down.

One tenant is on a 12-month lease, the other on a month to month and I plan on raising the rent of those on the month to month by 10%.

One I had a retired couple agree verbally to 1-1/2 month, hemmed and hawed about it, and they're suppose to bring it to the lease signing with the first months rent.

Perhaps raise the rent to $1500 now (assuming she's month-to-month and there isn't the rest of a lease term to honor), and talk about raising it to $1600 the year after.This would get you more income without any rehab/vacancy costs.

The 8 mobile homes are on lease-to-own contracts with the existing tenants, and the homes were positioned to the tenants as effectively being their homes; if all goes well, the tenants will make all required payment for 10-15 year periods, and will gain title to the homes at the end. 

(c) If personal property remains on the premises following the relinquishment of the premises by the tenant, the following shall apply:(1) If there is acceptance of the real property by the landlord under subsection (a)(1) and the writ or order of possession contained notice of the provisions under subsection (b), the landlord shall not be required to provide further notice to the tenant.(2) If there is acceptance of the real property by the landlord under subsection (a)(2) and the lease or lease addendum contains notice of the provisions under subsection (b), the landlord shall be required to provide written notice to the tenant that personal property remains on the premises and must be retrieved by the tenant.

I understand the OP is not buying or leasing the equipment. 

We came to an agreement that we would amend the lease and use her security deposit to cover May's rent, if she agreed to leave 6 June (lease was through Oct). 

My rental property manager leased an apartment to a lady who at the time had no pets. 

Has anyone done a sandwich lease option in Buffalo?