If something was for sale, I knew immediately what the ARV was going to be, based on the address - that was before zillow - and what was all around it.Farming an area in the past also helps me being able to buy sight-unseen, from across the country, as I've been doing.

I have evicted people through the whole process, just on principle alone, so that no one else can get screwed like I did.

I assume that I will need to keep those principles in mind when looking for the house; since I will have to combine what I want in a home along with the cash flow ideas?

If you don't need the cash, paying down the principle on your primary gives you a 4.15% return, the money is still available, depending on how much of a HELOC you want in proportion to the equity you may have some up front costs the HELOC including an appraisal, sometimes some of this is negotiable with the bank depending on circumstances and relationship.

Great advice on the common areas - I have also been know to "Shop for an apartment" in a target multiplex in order to see a little more without having to make the offer - but honestly, I had got to the point of just making offers sight unseen until one is accepted.

The sight didn't show how you install it.

That "rule" basically tells you to allocate half of market rents toward the total of expenses, vacancy and capital expenditures; the other half of market rent goes to debt service (principle and interest) and whatever remains is the net cash flow.

Yeah I have been using Zillow and similar sights to check out available listings.  

This was a sheriff sale property, so we bought the house sight unseen (well, besides the boat, trailer, and car in the yard which were pretty hard to miss😀) . 

It's also short-sighted.