Retrievability: Planning from the bottom up and the top down

Sometimes I think I over think things. I think it's the inner artist in me that wants everything to be 'just so', or maybe its the inner engineer wanna be that wants to over design everything to allow for future repair, maintenance and manufacturers recalls. Whatever it is, it's making me feel like I'm trying to run in knee deep water.
I have a vision of the interior, what things are going to look like. But I can't seem to get to the point where I start shaping the interior to my vision because I am constantly saying...."oh before I do this I have to make sure that we can access this, or repair that!"

For example:

Your typical fuel sender. A relatively inexpensive part. Easy to install, easy to replace. But once the fridge is installed, there is no pulling the floor up, which means to access the simple repair of the fuel sender, I would have to drain both fuel tanks and then drop the passenger fuel tank down to replace.

So I said to myself...."Self? would you rather drain and drop fuel tanks or move a fridge?"
So I created a little trap door under the fridge location to allow for the (hopefully) unlikely event of having to replace the fuel sender.

Same goes for the battery bank. I could drop the battery box down from under the bus.....but what a pain in the keester that would be...and access to the batteries is a very common need. So again another trap door

 The wall panels are a little different. I want them to be retrievable but the likely hood of these ever coming down is slim.(famous last words I know)

I also however want the panels to have a bit of a feature look to them as well. My sister in law (Adele) and little bro Shawn, came up with the idea of a recessed accent which can double as a mounting system for wall panels

Thankfully my planning had me design wood inserts in the ribs at 9",19"29" from the floor up. So I could install threaded nut inserts(yes think Ikea style fastener)

Then a 3" band of 1/8" aluminum is fitted to each rib, allowing for the panels to be fastened to the edges of the aluminum band, leaving a 1" recess showing the dome head bolt and the shiny metal as an accent. I love it when a plan comes together....almost.....oh CRAP!!(more to come)