Regarding water in your bilge. I personally don't like or trust drippless stuffing boxes and it may in fact be leaking. Some tend to blow a mist when the prop is turning. Sometimes they do not seat correctly--but you should be able to see water dripping from it or spraying when the prop is turning. IF you don't see water dripping from it and all your thru hulls are new, I would suspect the stuffing box for the rudder post. It may need adjusting. It uses an identical sutting box to the engine stuffing box but these are rarely serviced becuase they are so hard to get at. So it may need to be adjusted, or worse, the hose may be leaking or the hose clamps maybe loose or broken. Other than this area, are you sure that your knotmeter paddle thru hull is not leaking and the same for your depth sounder?
The two aft vents: if your engine is gas, then you need to run new hose from one vent to your bilge blower (it is usually inside the port cockpit locker) and from your bilge blower to the bilge under your engine. The other vent doesn't need any hose on it. If your engine is a diesel, you don't need to have the bilge blower, nor any hoses at all. The engine is well ventilated from the bilge for a diesel engine.