-I am up front with them about exactly what to expect as a tenant-I make it clear that they are a potential customer, and I intend to treat them as such, as long as they understand the nature of the lease and reasonable requests. 

I think it's a good place to start and a natural progression:1.

Here are some disadvantages of SFR compared to MF:- not as easy to scale to a large number of doors (very few people will own more than 30-50 SFR)- more paperwork: one mortgage and one insurance policy for every single tenant- value is only a function of appreciation, forced or natural, not a function of income- only one tenant under each roof The last argument only holds water for medium and large MF, because on a duplex the roof is literally (almost) the only thing you don't have duplicates for: 2 kitchens, 2 bathrooms, 2 HVAC etc) - Many of the arguments made for MF do not apply in my opinion for 2/4 family (Small MF).

The long-term tenant, the 99% government funded section 8 nature of the tenant, and the instant positive cashflow of $650-700 per month on a $1,000 rent.

Even though my LLC will show it was created in 2018, I assume that a lender would accept tax returns from the previous LLC if the name of the business, clients, and nature of the business all remained the same in the ownership change. 

The sagacious tone of the content I found to be very insightful, and the lighthearted delivery is very efficacious in nature. 

I am also looking at a property that is "luxury" in nature (relatively speaking - not Manhattan luxury, just the rents are $1,100 to $1,500) , and wonder if that's a bad move if the economy turns.

I couldn't answer any of these without knowing what coverage is provided by your HOA and what your insurance policy covers.I know an HOA that only covers the exterior and common areas, but only due to natural decay.

So, to summarize:Very loud and disruptive tenant (domestic disputes in nature).Potentially has one to multiple people not on the lease living there now.Defensive and unapologetic behavior when I speak to her.Pays on time.I have a lease with her that ends June 30th.The lease mentions Household Size and that any adults, or otherwise, living there apart from the tenant can only be allowed to live there by the written consent of the landlord.

It seems pretty discriminatory in nature and a violation of fair housing laws.I think your first step is to talk to the board, explain the situation, and see if this change will impact you.