I hope your doctor cleaned you up as well as my wiring!Your wiring reminds me of my angiogram.
Separate thrus and seacocks are preferable but if the boat doesn't have a raw water system and therefore no thru hull, it is easier to use one of the existing pickups like the livewell for the source of sea waterMy 2003 228 has two thru hulls and the live well is on one and the raw water wash down is on the other.