If you want to use the entire multi for the exchange you'll need to create an arms length rental agreement with your daughter. 

I bought this house when i was 23, and the first night i owned it, i sat down in the hallway and cried because I thought I made the biggest mistake of my life. 3/1 ARM, A/C venting from wall outlets, terrible kitchen, etc.Today, this is one of my best performing properties in Oklahoma and has appreciated in value by $40k.

It must be an "Arms Length Transaction." 

You definitely want to be perceived as the "good guys," especially if this does have to go to court, where your adversary will come armed with all your communications and actions to paint you as "bad guys."

Make sure it explicitly explains the process for termination if you are unhappy with their services, but especially if they violate the terms of your agreement.3.

Most commercial I know are amortized over a set number of years with a 5 year arm.

HELOCs are ARMs but you only pay interest on the amount you have drawn, cash out refinances can be a 30YF but you pay interest on the full amount you pull out starting on day 1.

Come armed with a list of questions.

right now I'm at 3.25% on my original mortgage, and I have 1 year left until the ARM goes up.

1st Lien - $125,500 - 6.25% - Montly payment - $771.90Sale Price - $175,000 - $1000 contribution = $174,000Down payment - 10%2nd Lien (our finance) - $157, 500  - Interest rate - $9.95 , 8/1/1 ARM - 20 year AmortizationMonthly  Payment - $1425.66, Escrow paid by BorrowerCashflow: $653 (before tax) - That's damn good cash flow.