Preheat oven to 400°. In a small bowl, mix butter and oil. Brush a 15x10x1-in. baking pan with some of the butter mixture. Place 1 sheet of phyllo dough into prepared pan; brush with butter mixture. Layer with 7 additional phyllo sheets, brushing each layer. (Keep remaining phyllo covered with a damp towel to prevent it from drying out.) Bake 5-7 minutes or until golden brown (phyllo will puff up during baking). Cool completely., Finely grate enough zest from lemon to measure 1 tablespoon. Cut lemon crosswise in half; squeeze juice into a bowl. In a large bowl, toss peaches, strawberries, pineapple, brown sugar, salt, and lemon zest and juice. Remove strawberries; thread fruit onto 3 metal or soaked wooden skewers., Place fruit on oiled grill rack. Grill, covered, over medium heat until fruit is tender, turning once, 8-10 minutes for pineapple slices and peaches, 4-5 minutes for strawberries. Remove and set aside., In a small bowl, beat cream until soft peaks form. In another bowl, beat cream cheese and confectioners' sugar until smooth. Fold in whipped cream. Spread over phyllo crust. Slice grilled fruit; arrange over filling. Sprinkle with mint; cut into pieces.