Combine feta cheese, 2 tablespoons olive oil, half the lemon juice and zest, half the red pepper flakes, 2 cloves minced garlic, and mint in a food processor. Blend until smooth, adding more olive oil if needed. Cover and refrigerate until ready to use.
Put shrimp in a Ziploc bag. Add remaining olive oil, lemon juice and zest, garlic, and red pepper flakes. Add oregano. Seal and refrigerate 2 hours.
Slice french bread into 1/2 inch slices, cutting diagonally to get desired size. Brush with olive oil and toast lightly.
Pour a tablespoon of olive oil into a pan over medium high heat. Once hot, add shrimp and cook until just opaque, about 2 minutes on each side. Remove from heat and set aside.
Spread feta mixture onto each slice of toast. Top with roasted red peppers, kalamata olives, and one shrimp. Garnish with lemon zest and sliced mint if desired.