This allowed us to cut the cost of our rent substantially.At the apex of the rental year in Washington, D.C., we can net $2,800 a month just by renting out our basement.

Our existing mortgage on that house (15 yr at at 4.25%) will be paid in 6 years and yesterday I was quoted a rate of 4.75% for a cash-out 30 yr refi.Tax considerations: we've owned the existing property as a sole proprietor and the Tax Cuts and Job Act has me considering LLC or even possibly C-Corp for tax benefits.

What really upset me is that this wholesaler guaranteed several things to an unsuspecting homeowner and straight up lied to him about multiple things, including the actual value of his home and what would really happen if he signed this contract.

Straight away, gotta do something about your emotional attachment.

With federal cutting the rates to zero, what to expect on high balance mortgages (loan amount above 500k since its pretty common in bay area). what interest rate to expect to refinance and new home mortgages ?

While I am not surprised rates were cut to zero - bank reserves were also cut to zero as well.

That will likely do more for the market than another rate cut. 

We have considered just staying put in our current house in which we have a tenant that lives with us and basically cuts our mortgage payment in half with their rent payment.

All discretionary purchases are on hold, and I'll be reviewing my recurring/subscription billings to cut charges that are no longer needed. 

And the others see long term dire straights.