I am looking to buy mixed used building. Is it possible to obtain short term seller financing and then re-finance to cash them out? I can also bring large downpayment from 1031 exchange from an owned commercial property that I have.
What other options for financing eitherprivate or bank?

Financing options vary from deal to deal. I couldn't give you a YES or NO. You have to do due diligence and work the deal to determine if you have viable exit strategies.

This process should be completed on every deal.

Usually my buyers have a step by step process. If it survives the process they might do a deal.