BEFORE THE FLT, THE PLT & PAX WERE OBSERVED DRINKING ALCOHOLIC BEVERAGES ON THE WAY TO THE ARPT. AFTER MUCH DIFFICULTY TAXIING TO THE RWY, THE FLT WAS CLEARED FOR TAKEOFF AFTER ENTERING THE ACTIVE RWY WITHOUT CLEARANCE. AFTER TAKING OFF, THE ACFT WAS SEEN DEPARTING WITH THE GEAR STILL EXTENDED. SHORTLY AFTER DEPARTING, WITNESSES SAW THE ACFT NEAR A LAKE FLYING ERRATIC WITH THE RGT ENG SPUTTERING. SUBSEQUENTLY, THE ACFT DIPPED DOWN TOWARD THE WATER & MADE A RGT TURN. AT ABOUT THAT TIME, THE RGT WING CONTACTED THE WATER & THE ACFT CARTWHEELED & CRASHED. AN EXAM OF THE RGT ENG REVEALED THATTHE FUEL INJECTOR LINE TO THE #6 CYLINDER HAD FAILED UNDER A RUBBER GROMMET DUE TO FATIGUE. ALSO, THE FUEL SELECTORS WERE FOUND POSITIONED SO THAT BOTH ENGS WOULD FEED FROM THE LEFT OUTBOARD TANK, A CONDITION THAT WAS NOT RECOMMENDED FOR TAKEOFF. ADDITIONALLY, THE RGT PROP HAD NOT BEEN FEATHERED. TOXICOLOGY TESTS SHOWED THE PLT HAD A BLOOD/ALCOHOL LVL OF 289 MG/DL (0.289%) & THE PAX HAD 146 MG/DL (0.146%).