1) The regulation 1.263(a)-(f) reads that you're able to utilize it for amounts paid during the taxable year.

If you're total taxable gain is relatively small, then it is easier to justify paying the tax and avoiding the headache. 

I started doing this a couple of years ahead to reinvest and drain the taxable balance down.

. $500k becomes $350k and throws off taxable NOI, etc.)

But with showing minimal taxable income over the last 2 years, it's now hard to qualify for any type of traditional bank refinancing.

You can't combine Roth and Traditional money in one account unless you do a Roth conversion, which would be a taxable event.There is no one-size-fits-all when it comes to investing using your retirement funds, but you certainly can own rentals with leverage in an IRA and this can be very profitable. 

Debt is not taxable income, so there should be no taxes due.I'm no lender, but you will need an asset-based loan like DSCR (debt service coverage ratio). 

In a 1031 exchange, you could receive cash that is taxable.

Otherwise any cash you keep would be taxable.  

To get this, I’m paying them about 10% over asking price in total purchase consideration, but the terms and monthly payments are so favorable that it really doesn’t make much of a difference.Although I’ve read extensively about these deals, this would be my first and my big question is around the taxable basis of the property.