$6k tax.Ins,hoa, not to mention utilities . took out a HELOC off of our personal home ( res.worth $900k, and a 260sq ft studio, mtr. $1450 mo.) for$ 220,000 for the deposit.

Imagine making millions of dollars over the course of your career and then having to pay 30-50% every year to uncle sam instead of compounding that cash over time.This is exactly what real estate professionals have learned to mitigate.To reduce their taxable income, they just buy a building every year, do a cost seg, and use depreciation to reduce their tax liability dramatically.Their personal wealth snowball grows much larger and much faster than their W2 counterparts who give most of their money back to the government each year.Following this strategy as a real estate professional is one of best ways to end up with a much larger net worth at the end of your career.

The person I would seek advice from is a CPA about this. 

I would recommend anyone lending in this environment to fix and flippers or any type of investment to be careful and get a personal guaranty and make sure person has a long track record.

Personally, if I were to sell the stock, I would buy more property, not pay off the existing one. 

I personally have success in doing flips with my partner here in Ohio.Lakewood and Edgewater are gentrifying neighborhoods in Cleveland.

I think it's just for text, not to talk with a live person.

Is 10-15 miles too big of an area when determining the unit count per person?

My personal preference for a buy and hold would be an already established area (or an area that's still gentrifying, but has already seen significant progress). 

A new person moves in and she says the upstairs neighbors are creating a ton of noise.