I do not believe that you would be able to deduct entirety of the food bank donation or the Komen donation. The problem with the food bank donation is your reduced basis because your net cost of the purchase is reduced because you received frequent flier miles in return.

The problem with the Komen donation is that it is a sale -- you paid money to the charitable organization and received something in return. For tax deduction purposes this limits your deduction to the amount paid less the fair market value of what you received.