To determine the correct treatment, consider the RV's permanence, utility connections, and business use.This post does not create a CPA-Client relationship.

I mean myself and any bank would need more details, but if you utilize that large sum as a downpayment and have a small mortgage, wouldn't you easily qualify for the debt to income?

To minimize capital gains tax on the sale of their primary residence, your in-laws can utilize the $500,000 capital gains exclusion, potentially explore an installment sale to spread tax liability over several years, or consider converting the property into a rental to use a 1031 exchange for tax deferral eventually.

Utility deposits?

If you made housing free the same bleeding hearts would be complaining about utilities.

Utilities included.Fully rented.For sale off market.

Another option would be to utilize a property manager to manage everything and keep a buffer between you and the tenants.

You're marking the equities to most recent returns, the reality is a real estate investment to live in is a guaranteed rate of return and serves utility. 

The “work around” in those states requiring licensure is usually to utilize an incensed mortgage broker in that state as originator/broker while you’re the lender.

@Will Almand this sounds like a very useful case for cost segregation especially if you can utilize the depreciation expenses against your income.