You are under no obligation to close in a refinance - and there is no point of no return along the way. Fees may be lost, but that wasn't the question.
The appraisal on a conventional loan, regardless that you paid for it, belongs to the bank. Period, end of discussion. If it was a VA or FHA appraisal (and paid for), you can request it be assigned from one lender to another. If it's a conventional appraisal, the most you can hope for is a copy of the appraisal. The copy will be in the name of the bank that ordered it and the appraiser MAY NOT re-address it or put another bank's name on it. Nor, will most banks accept an appraisal in someone else's name. Now, if the new lender still has the freedom to order their own appraisals, they can contact the original appraiser with a new order (and if he/she accepts and does not feel it's a conflict).
As for application fees and lock fees, well, unless the loan is denied, they will be toast, too.