(will post the remaining updates throughout the day).

I have private money lending at 6% that will fund the rehab and I want to ensure that I am calculating this correctly.Rent - Mortgage - Insurance - Tax - Vacancy(10%) - Maintenance(10%)1350 - 440 - 50 - 210 - 135 - 135 = + 380Cash on Cash return (initial):380x12 = 4,560 / 40,000 (down-payment + rehab) = 11.4%Cash on Cash return (after rehab and appraised at 120k) New Cash Flow using refinancing with 80/20 conventional:1350 - 530 - 50 - 210 - 135 - 135 = +290290x12 = 3480 (per year)Total Cash invested:Down Payment + Interest to Private Lender + Cost to refinance (4% of remaining principal)   24,000+1,200+ 3850 = 29,050New Cash on Cash: 3480 / 29050 = 11.9%Major concerns are not knowing which way the area is trending and not getting any sort of discount on the rehab.Any input would be greatly appreciated.

The second I sign the closing docs and the title is transferred my initial cash I'm investing becomes equity.Equity by nature is based on value and principal remaining on the loan, it's the difference of the two.  

Yes he can create a limited partnership and give the main interest to his son and still remain in control of the  property so when he sells the property he will only get taxed on the percentage that he owns.

You are left with a remaining 50% of gross rents this would be your cash flow/Income/profit per door.

Others may think you are not worth the time as you are just window shopping at the moment.Just like you do not owe it to any particular agent to be their client no agent owes you anything in regards to satisfying your need to see the properties.

And in, say 10 years, you can always refi your remaining balance into another 20 year loan and reduce your payments that way as well.Lets say you buy a house and your mortgage is 100k as a 20yr loan at 5% - which is pretty typical for my local banks these days.

I see people saying that the title is free and clear, does that mean I do not have to pay the remaining balance on the mortgage? 

I obviously understand that there will always be deals, I am just trying to remain realistic as I am building my business plan.

Also, if the property is underwater, you could sell off the remaining UPB at a deep discount, 3-9 cents on the dollar, if you wanted to be scrooge about it.