Here the only way to collect any fees in court is really charging them as rent. 

This also gives you the option to flip income to your wife at a later time if you want her to have higher income to qualify for a mortgage when you're tapped out (not tax savings but good to have the holding LLC).You can also have your tax bill charged to the holding LLC for a portion which is tax deductible while your 1040 tax prep fees are no longer deductible with tax reform. 

Wouldn't they just automatically charge their seller their 6% for both sides of the transaction since you don't have your own realtor? 

If I were to acquire the property, what would I have do to make this a legitimate (and safe) dwelling without putting myself at risk?

Since they have moved in we have been charging them $1500.00 per month. 

The reason for this is the lending laws to owner occupied borrowers are significantly different than lending to investors - examples foreclosure process, rates and fees that can be charged and no balloon payments.If you do fins someone to lend the money needed, I would highly recommend that you have a competent mortgage lender take a very close look at the deal so they can get you refinanced out of the private money once you have the rent revenue in place.

Some states charge a fee, some are free.

--They will typically take 3-5% of your income, as well as charge a guest fee of 5-10%.2.

Assume an accredited investor and no securities law issues for simplicity.1) Homeowner pays for a legitimate appraisal.2) Homeowner grants the right to Investor to receive 10% of any appreciation above the appraised value when and if the house is sold.3) In exchange, Investor pays the homeowner an amount equal to 10% of the appraised value, with 20% down and the rest on an interest-only promissory note held by Homeowner.4) The note bears interest at Prime + 0% and does not have any origination fees or prepayment penalties.5) The investor gets credit for 10% of the eventual net proceeds from sale with the net being 10% of net sales proceeds less the remaining balance of the loan.6) If the investor defaults on the loan and fails to cure the default, the claim on the equity is forfeited.7) The homeowner remains fully responsible for costs of maintenance, insurance and taxes, but this is offset somewhat by the interest on the loan and the cash received upfront.8) Presumably if there is a gain beyond the homeowner's basis, there is no tax for now unless the proceeds exceed $250k for an individual or $500k for a couple.

I'm not a grue that charges for my experience but also do not waste my time looking for free advice.