With that much "profit" available in the deal, if needed we could sell even in todays market, at below market and still profit.

Long story short, you can, but since you are only targeting investors, your sale price will likely be lower than comps.Talk to a local agent about your local tenant laws and have them review their lease

These costs for most of the individuals are considered personal in nature (unless you have a RE portfolio that is run like a business; see below).

If tenant below is paying 1,500/m he's living in area he wants for roughly 750/m P/I payment.

When tenants stay for ten years, it's usually because their rent is well below market rates.

Both programs can aggregate data based on filters like zip codes, sell scores, etc. 

Pretty much every small business other than some obscure ones that are excluded (see below) If you have 12 Single Member LLCs that own your rental properties.

Below.  

My replies to your questions are below.1.  

The rates will be lower and will allow you to maximize profits.