When you are pre approved for a mortgage loan, will it have any consequences if a home is not purchased? I don't mean getting a loan and using it on something else,


No but depending on lender watch out for application fees or any other non sense they may try to charge you. These May be paid at closing but YOU do not gave to pay if you don't purchase .
Not until you enter into contract. After that there will probably be penalties for backing out. Pre-approval means very little...you will find the process a thousand times more exhaustive once you enter contract.