But as for the seller finance, would the loan to the seller be the difference between 450k and the refinance number of 220k?

What loan size and loan to value?

total return from an RE investment includes value added, appreciation, tax benefits, equity pay down, and the cash flow. 

They have also outsourced their TAX SERVICES and despite my constant request to expedite my tax filing so that we can apply for a CRITICAL BUSINESS LOAN TO EXPAND OUR BUSINESS, THEY SAT ON OUR TAX and BOOKEEPING files for 7 months.

Credit Unions are pretty great, as in my experience, commercial loan renewals tend to be automatic.

When Trying to qualify for a traditional loan, lenders usually price your purchasing power at 3x your net income.

If you have considerable equity in the property or multiple properties it's even more important.

If leveraging equity feels too risky, you might consider using a portion of the equity to fund your next property while keeping reserves intact.

My duplex - built 1989, 2,060 sf, 2 bed/bath, 1 year old roof, value if I subdivide (county already approved) and sell each separately $150k each ($300k total)Investor duplex - built 1995, 2,300 sf, 2 bed/bath, 5 year old roof, value around $310kThe investors initial request was for an equal trade and they would pay realtor fees, which I replied wouldn't be equal due to buying/selling costs (recording fees, title insurance, closing fee, survey, inspections, loan fees, 1031 fees, accountant fees, repairs), taxes would increase due to new sale price, I'd trade a 3.75% mortgage for a higher one, and I'm on the 10th year of a 30 year loan so resetting that to a new loan would restart amortization and pay more towards interest.

If you close with a conventional loan, it will need to be in your personal name.