Basically, these are lands that technically qualify as Sending sites, but that have issues such that nobody really wants to build there.

And you do not technically have to replace debt. 

My recommendation would be to take business classes at a technical college while working/ interning for a company in a field you are interested in.

It is certainly beneficial to have someone local that you can call on for these emergency issues but don't see it necessary to have a full time PM in my opinion.

Technically you are going to be able to claim the interest, since you are the one that's going to receive the 1098-int, but what's likely to happen is that the buyer is also going to ask for/claim that interest and then you are both going to be in a jam with the IRS. 

Do you have any rust issue?

There's a good chance the issue(s) you face has already been discussed and answered.Ask questions in the appropriate forum.

The technicals (migration rates, job growth, tax situation, debt cost, etc) to work as well.

While these technically exist, these are typically difficult to execute and are very expensive.

The technical term is Sound Transmission Class.