I certainly understand your thought process.
I've been thinking about my own re-rig, and considering doing something with a plug-in, to be able to disconnect the entire thing, and then make up a "pig-tail" to connect in between if I need to troubleshoot a gauge.
I'm only going to be dealing with 6-8 gauges, and not a huge number of switches.
Did you go with 3-way momentary starter/ign switches instead of the key?
That's what it looks like - aircraft style protected switches (if that makes sense).
I was thinking of doing the same.