Here are the key data points:Park info  Located in Alabama61 lots25 owner occupied homes18 park owned homes (14 currently rented; 4 currently being repaired and should be rented soon)18 vacant lotsAvg lot rent - $160 (unknown what the market rate is but it doesn't sound like there has been a rent increase in at least a year, maybe more)Avg POH rent - $400Expense ratio - seller claims 26% but I'm estimating 35% for the lots and 50% for the POH'sCity water - individually meteredSeptic - good condition (allegedly); a couple were pumped last year, none this year (no lagoon thank heavens)Seller claims gross income $130k, expenses $30k, and NOI $100kI calculated gross income of ~$135k, expenses of $60k (55% on POH and 35% on lot rentals), and NOI of $75kOther infoMom & pop seller, but park is listed with a brokerPark has been on the market for > 3 years (recent price reduction)Greater metro area stats look goodPopulation = 115kMedian home price = $105kUnemployment < 8%Household income > $40kHousing vacancy ~ 15%Closest Walmart is 7 miles awayFreeway is 1.5 miles awayNumbersMy valuation is coming out about $80k-$100k under the seller's asking priceWith conventional financing I'd be hoping for a purchase price of $500k, $100k down @ 6% over 20 years (not sure if this is plausible or not)Assuming that financing, I'm expecting net cash flow of $40k (after debt service)Upside potential is in raising rent and filling the 18 vacant lotsFollowing the same assumptions above, raising rent $50 (if the market supports it) would change NOI to ~$90k and net cash flow of just over $50kFilling the vacant lots could potentially increase gross rent up to somewhere between $150k-$200k, depending on what the appropriate occupancy rate is for the areaWithout verifying any of the above information (haven't offered anything yet so there's a lot of DD left to do), the deal seems to make sense. 

This is because the properties are usually (but not always) distressed and require rehabbing before a conventional lender will touch it.  

I'm doing some work to the rental unit with the goal of charging close to/at market rate which is somewhat higher.  

From what I've read here, going conventional is ideal.

The sales price would be $200,000, the property rehab would be approximately $80,000-$100,000 and the ARV would be anywhere from $400K-$450K.I’ve secured preapproval for a conventional homesense loan but the closing time on that is 45-60 days.The seller needs to have a fast close so I’m exploring HML or other options.I’m a first time rehabber so I’ve noticed that most HML lenders have really awful terms for first timers.I’m in North Carolina and was hoping somebody could direct me to reputable lenders that will work with me.

You may be able to charge some of it back to the Tenant by having a flat fee for the water/sewer/garbage that is most likely included in the HOA fee. 

Was one parent in charge of making money and the other spend it?

If I had a CPA prepare my tax return and it is audited, I would expect the CPA to defend his work on my behalf without charge.  

The property will be obvious more attractive without additional fee charged to tenants.

But, see next bit about working off-market sellers for a commission.If I am working with investors looking to flip and I source the property for them, I charge the off-market seller a small commission for bringing them the deal and I run the deal as dual agency to keep the transaction friendly and on track.