RE: Extra wiring inside the Westy
I'll answer your question this way.
For any wiring/power needs I have inside the Westy they all come from one
place, right behind the drivers seat.  The only thing that has ever been
plugged into the outlet at the floor by the rear seat is the 30 amp three
stage battery charger that resides under the back seat with the aux
battery.  That stays plugged in and is not hard wired so that it can easily
be unplugged (plus I was to lazy to wire it into the back of the sockets and
have never found the current setup a problem).
Why all behind the drivers seat?  To keep from tripping over wires strung
across the living space.  I have a power strip for 110v AC mounted high on
the end of the cabinet with the cord going through the wide gap at the back
of the cabinet to the outlet that originally was used for the refrigerator.
I have the inverter mounted just below that and hard wired to the extra aux
fuse box I installed at the bottom of that panel.  And I have a multi outlet
12v 'cigar ligher' outlet mounted just under the inverter.  So when camped
and I need to plug something in ALL the wires are in that corner or come
from that corner.  All out of the way, nothing to trip over and nothing to
get pulled off a table or sink top and broken.  For the way I stock/pack the
rig and the way I use the interior this works great for me. YMMV