After repositioning they 45k to 100k in per door depending on area and rent.

It will depend on the type of loan. 

Deduct NEW property taxes after you buyDeduct home insurance costsDeduct maintenance percentage, typically 10%Deduct vacancy+tenant nonperformance percentage(we recommend 5% for Class A, 10% Class B, 20% Class C, good luck with Class D)Deduct whatever dollar/percentage of cashflow you wantNow, what you have left over is the amount for debt service.Enter it into a mortgage calculator, with current interest rate for an investment property, to determine your maximum mortgage amount.Divide the mortgage amount by either 75% or 80%, depending on the required down payment percentage - this is your tentative price to offer.If the property needs repairs, you'll want to deduct 110%-120% of the estimated repairs from this amount.Be sure to also research the ARV and make sure it's 10-20% higher than your tentative purchase price.As long as the ARV checks out, this is the purchase price to offer.It is probably significantly below the asking price.

It all depends if you are okay sitting on it for a little while.

It really depends on what they specifically need.

I would anticipate roughly 20-40k depending on how deep you have to go.

The choice depends on their priorities simplicity now or long-term tax advantages.

Prepayment penalties are a thing of the past, so dump your bitcoin into paying down the balance (and, possibly, dropping the PMI) after the fact - no one sources where you make your normal monthly mortgage payments from.It's going to be in limbo and a giant "it depends" until such time as someone opens a Bitcoin clearing house that does all the little compliance and PATRIOT Act things that Wells Fargo and Fidelity do, or (more likely) until such time as Fidelity or Wells Fargo adds Bitcoin to their financial service offerings. 

Again, these fees are charged and paid to the lender to complete and fund the mortgage.Third partyclosing costs include title company fees - including the actual title policy, escrow or closing fee, tax certification, and other title fees; governmental charges – including recording charges, intangible, and transfer taxes (depending on your state).

@Saurabh Kukreja it all depends on what your goals are.