Those connections are amazing!
I have switched to a plastic tub for running the boat in the driveway. That provides a sufficient water supply.
Once you can keep the engine running and warmed up, I would check for a vacuum leak around the base of the carb. Using a little caution, spray carb cleaner using the provided straw around the base of the carb. If the idle speed up, you found a leak and need to replace the gasket. Remember there are two gaskets on either side of the spacer.
As far as the idle mixture goes, the base setting for the mixture screws is 1.5 turns out from lightly seated. This will make it run reasonably well, though a small adjustment might be made searching for the sweet spot.
The choke should blade should be lightly closed on a cold engine, and should be fully open within a minute of start-up. Power is supplied to the choke housing and will open the choke regardless of whether the engine is running, so pay attention to key position.