the fast clicking means low power to the starter, check your connections at the battery and starter.
The water contamination, simple fix, its really no big deal. wipe the push rods off, blow through them as well. clean what you can with carb cleaner and a rag, drain all the oil out of the engine, put on a new oil filter, add 2qts of 10W30, run it full throttle for 20-30 minutes...the heat should boil/steam off any remaining moisture in the system. This is common on commands that are started often, but not run more than 1-4 minutes, as the engine gets warm, but the oil stays cool, condensation forms in the engine, and it runs down into the oil. On our floor model tractors with Kohlers...we would crank them 2 times a day, once to move them out, once to move them in, running about a minute each time. We would gain about 1/4" on the dipstick in moisture a year, and would drain out thick chocolate milk when we had to finally change the oil due to smoking.