Crumble smoked salmon into a medium mixing bowl. Stir in lemon peel, lemon juice, capers and olive oil. Season to taste with salt and pepper. Quarter and slice cucumber into bite size pieces. Roughly chop fresh dill. Refrigerate all toppings.
Start charcoal fire or preheat gas grill to medium-high heat.
Combine 1 cup flour, undissolved yeast, sugar and salt in a large bowl. Add very warm water and oil; mix until well blended, about 1 minute. Gradually add enough remaining flour to make a soft dough. Dough should form a ball and will be slightly sticky. Knead** on a floured surface, adding additional flour if necessary, until smooth and elastic, about 4 minutes.
Divide dough into 16 portions. Pat or roll dough on a well-floured counter to about 4-inch circles approximately 1/8th-inch thick; they do not need to be perfect. Brush lightly with oil.
Using hands, lift each crust carefully and place on grill, oil side down. Cook for 2 to 3 minutes until bottom is lightly browned and top looks set. Using long handled tongs, flip crust, brush lightly with oil and grill an additional 1 to 2 minutes or until crust is lightly browned. Remove crusts from grill to a platter or baking sheet.
Evenly spread cucumber-dill cheese spread onto each pizza crust. Sprinkle each with smoked salmon mixture.
Place pizzas back onto grill. Grill an additional 2 to 3 minutes or until crust is crispy. Top with cucumber and fresh dill. Serve immediately.
*If you don't have a thermometer, water should feel very warm to the touch.
**To knead the dough, add just enough flour to the dough and your hands to keep the dough from sticking. Flatten dough and fold it toward you.Using the heels of your hands, push the dough away with a rolling motion. Rotate dough a quarter turn and repeat the "fold, push and turn" steps. Keep kneading dough until it is smooth and elastic. Use a little more flour if dough becomes too sticky, always working the flour into the ball of dough.