And the fee for the tenant to break up payments is reasonable.But I am not clear on how the landlord would still get paid (in full?)

That might be a conversation to have with them, they both will stay on the lease if they break up and if only one stays in the property, the eviction process will fall on both of them if they fall behind on rent. 

It's not difficult to meet somebody and quickly know they're not the rowdy type.As a landlord, I  always tell my tenants that if they break up or friendship ends it is not my concern. 

For reference, I'm using a cash basis, not accrual.When making loan payments, I break up the line items as shown below.

I have two this year: one due to a marital breakup and one due to loss of a job.

People break up and divorce all the time.

if they break up, it's not your issue and you can collect against whichever one you want.

Sometimes breakups result in some unusual behavior:Woman trashes her wedding dress with paint after canceled wedding

You could sell part of the extra acreage off to get funds for your down payment, you could break up the property in several parcels and then the lender will have first lien position on those parts.

Many investors choose not to work with agents and that's fine but as far as trying to break up a seller - agent relationship is wrong.