Bilge Drain & Cockpit Drain Question - Ericson 23'

Currently the bilge is not hooked up - I've purchased a Rule 1500 with associated float switch. I'm trying to determine the proper "plumbing" so I don't have water coming back into the boat while sailing. Additionally I have a constant 1 - 2" of water in the cockpit recess and I don't know where that's supposed to drain (it does not appear to be draining). There a valve assembly that I currently have shut off to prevent water from back-washing into the boat; not sure if that is supposed to be there or not. Feedback is deeply appreciated; I want to plumb the vessel correctly. I have attached photos of the valve I found.