Ah, I see what you mean. So they riveted the platenuts through the edge of the seat & baggage pans already. I wouldn't bother removing them...just pop rivet the rest of the open holes.
For wiring, yeah, I did run one conduit under the seat/baggage pans through F-705 and F-706. I needed a little more room to run strobe wires since I have one power supply aft of F-706. It's hard to anticipate your wiring needs until you figure out where everything goes and just how big the wire bundles end up being.
I cut an access panel in one of my baggage floors to run the conduit. I'd only recommend doing that if you absolutely have to. You may not need any additional conduit above and beyond the snap bushing runs in the tunnel.
I'd just wait and see how it goes...
)_( Dan
RV-7 N714D
http://www.rvproject.com