i`ve never used a packaged pie crust, so i can`t comment on that aspect, but i always grease my pie pans. along with an initial 5 minutes or so at a very high temperature, it helps to crisp up the bottom crust. it would probably help with the sticking, too.
as for the foil on top, i`d say just make sure it only contacts the uncoated pecans, and not the filling, and that you might need another 5 minutes or so baking( i`m sure you`re an expert eye-baller of fillings).
best of luck next time