Is it permissible to eat food sourced from a father's money deposited in banks and mixed with usury? Is it permissible to take from this money to complete the construction of a house? And is traveling to work in another country with the intention of performing the Hajj pilgrimage and earning lawful money considered disobedience to a father who refuses the travel?

Dealing with someone whose wealth is mixed is not forbidden. Therefore, there is no harm in working with your father and accepting his gift, while continuing to advise him to repent from dealing with usury. There is no harm in your travel for Hajj and seeking sustenance without his approval, unless you fear he might be lost or if your travel involves destruction. It is commendable to strive for his approval and contentment.