In a food processor, combine the vegetables, herbs, spices, salt and sugar and process to a coarse paste. Keep the processor running, and add the the soy sauce and oil in a stream. Pour the marinade into a bowl, add the shrimp and toss to coat. Cover and refrigerate at least one hour and no longer than two. Bring the shrimp to room temperature before grilling.
While the marinade is in the fridge, soak 20-30 wooden skewers in a tray filled with water. You'll be using two skewers in parallel to keep the shrimp flat while grilling. The quantity depends on the size of your shrimp. Five shrimp per each pair of skewers is right for large, six for medium and four for jumbo. So soak the proper number of skewers for the number of shrimp you have.
When the shrimp are well-marinated, remove from fridge and bring to room temperature. Drain excess marinade. Then thread shrimp onto first skewer, sliding its pair in parallel once the first stick is done. Best to keep heads and tails pointing the same way. Continue until all shrimp are on skewers.
Light a grill (outside or stove top). Grill the shrimp over a medium-hot fire,turning once, until well browned and cooked through, about 3 minutes on the first side and 1 and a half to two minutes on the second. Feel a shrimp to see if it's firm to test for doneness, but be careful not to overcook.
Remove the shrimp to a platter and serve with lime wedges.