The lower purchase price helps me REFI more money out of the deal and increase my COC return but doesn't affect the cash flow after REFI....

(House-A)I want to buy another (House-B), and then sell House-A.My lender has pre-approved me or a mortgage for another house (House-B), without requiring me to sell my current house, (House-A)I want to do a BRRR and buy House-B with hard money , renovate and then utilize the mortgage to lower the interest rate and pull out most of the initial investment.If I borrow from the hard money lender, will that reduce my borrowing power for the new mortgage?

I agree with Brian, if you want to be a good landlord and not just a slumlord ask yourself what is the number that gets yourself off the couch to get the property repaired and to keep it up nice so you get good renters and lower vacancy.

Since we are taxed on the interest portion of the repayment, the further towards the end, the lower the % of the P+I payment that is interest. 

Unless the property is on a waterway or lake, I would look for another property.BUT, its a different story when you can step out back, lower your boat. 

But with that being said - would you rather go in white collar areas with a higher risk of tenants losing their high income or should it be a blue-collar area where jobs are more stable, but cash flow is lower?

I would only be aggressive with leverage if you were really comfortable with the actual investment and it was a lower risk opportunity otherwise it could all blow up in your face.So if you go by the math alone- leverage, leverage, leverage.

As many of you are aware, if you own a building in your own name, 1-4 units, you can often get great "FNMA type" financing where you get a decent interest rate, lower DP, and literally locked in with no rate changes for 30 years.

When you raise rents each year starting out at lower rents you tend to still be the best priced in town.Conversely the higher priced rents the property tends to be extra special, or a new build with amenities,etc.

One, that is 10k more than mine, and another one that is 15K lower, but needs a lot of improvements.