Over a 7 year period I think it will be an attractive investment.  

A Realtor is just a designation you get for joining NAR and paying their dues. 

It is a Depression-Era, 1930 single family home with Art Deco design elements located about a block from the city's rejuvenated downtown area, where there are shops and restaurants, and across the street from The Siloam Springs Museum.

Any suggestions on how to be more attractive to the lender so we can keep both? 

I'm looking to redo the lawn on the property with native garden and changing some of its design like walkway, etc.

One thing to keep in mind if you do rent is the type of clientele the units will attract and if you're comfortable working with that type of clientele. 

A spread of 2.5% (5 x what they're getting today) might look very attractive, and still leaves 1% for the deal maker.  

Build a relationship with them. 2) An agent could work as a designated agent (solely representing you),  dual agent(I would NOT do that), or transaction broker(they represent the transaction but give NO advice)3) No difference between the process.4) Financing is the same just walk it before offering. 

I'm aware that RV parks are already on a faster depreciation schedule, and that's a great reason for why i am attracted to them.

You may not "need" to do these improvements, but nice units attract nice renters, crappy units attract, well, you know.