It will be great to have future access as well as clear pathways for the bilge pump hoses. One trick from WHK is to run the electric bilge pump outlet to the sink drain using a standard kitchen dishwasher fitting.

I get the impression from your description and the pictures that you are rebuilding the sole to be flat. Without standing inside my boat I am fairly sure (but not certain) that the original has a gentle curve from sides down to the bilge cover. I would assume a flat floor would be easier to install, but you lose out on drainage and some extra height clearance--inch or two makes a difference if you are in the 6 foot range.

I only realized after all these years that the port settee is wider than the starboard side, at least on hulls 460+. In your pictures you can see the bilge is not centered relative to the floor--there is more space to starboard than to port.