what I like about MLS is you can go through a normal buying process. .wholesalers want to hype their deals info is wildly incorrect.. they want up front NON refundable deposits and your not getting any of that back.. they just try to create a false sense of urgency.MLS you take your time make your offers you can offer less you protect your EM you have inspections you can re trade within your contract time lines etc etc..MUCH more buyer protection that way.. the market will dictate the final outcome.. not a wholesaler hype machine and no real due diligence.

New home construction, and flippers are two sellers who the market dictates should fix every thing.

I agree fully with Andrew.You are confusing the legal laws under which an organization is structured, which is nearly always dictated by a given state, with the federal tax structure that the entity is operating under, which is dictated under the Feds.For income tax purposes an LLC is most often either a disregarded entity (wholly owned), or a Partnership (multiple owners). 

The expense factor will be dictated by your line of work. 

It would likely depend on state regulations that may dictate whether an owner/operator could live under the same roof as residents ( a casita or guest house may solve that issue).

Let's look at MSA median incomes, because reality is when "investing" in a MSA Real Estate, well, revenue and profitability will be DIRECTLY dictated by your customer bases ability to pay, right. 

Based on your time, energy and capital you have to deploy will dictate where and what strategies you can use.  

As to building on industrially zoned property, the local zoning regulations will dictate this answer under the allowable uses.

But all told, it is your market that will dictate what is needed.  

Your exit price on 2-4 units will always be dictated to a great degree by your cashflows, which isn't necessarily a bad thing, so long as rents have increased.