While they have been ideal tenants, I absolutely need to raise rent- as I said, it is currently well below market value.

I want to make sure the cash flow is good before investing all of it.I looked into a HELOC and that is what I ideally wanted but found that banks are either not doing them or your credit has to be impeccable to qualify.  

I hear NOVA is a little crazy but would NE/SE DC or Silver Spring / PG County be an ideal location?

Just curious I know the Market is Ideal for Vacational/AIRBNB etc so I know its very possible but just wondering what some peoples success or more importantly their Failures were. 

Ideally someone who is experienced with Strip Centers, trying to get a specific type of tenant.

Hard to pinpoint an exact ideal number of homes without knowing your entire management strategy.

Ideally, when it is time for you to move to your next rental property, those tenants stay in this property and you are now renting to them without occupying the same property.  

Our MLS has a decent enough auto-notification once searches are setup for a buyer, and beyond that we also get various other services that do that sort of thing for free that I don't use.

How about having landlord to cover tenant's medical bills, student loan and auto insurance for next?

In general though, if you're able to buy cash, do the rehab with cash (and avoid a "back seat driver" - IE the lender - during your rehab), that is ideal.