removing ballast resistor WIRING, MSD, switched 12v source,

You need the brown jumpered to the blue. I guess you could pull it out of the bulkhead and strap it to the blue "under the dash" which would clean up one whole wire. The reason you still need the brown is that on most older Mopars, the blue goes cold in "crank." Brown is the only "hot" wire supplying ignition power, so you still need something to trigger the MSD to "operate." "Trigger" in this case means triggering the power - up circuitry in the MSD, has nothing to do with triggering spark.

But you STILL need the blue "under the hood," depending on the year of your car and what's under there.

On the 70/ later cars the blue supplies power to

ignition (in this case MSD red trigger)

regulator power

alternator blue field wire

electric choke if used

Some smog doo dads on some cars, idle solenoid, etc. I don't remember where the A/C clutch comes from if used.

So in the end, there is not a heck of a lot that you can do away with.

You COULD clean up the blue where it splices off to things and hide that, along with a simple bullet, etc, connector for the MSD "small red"

Really, that's about it. After all, Ma didn't just throw a bunch of wire in there for the hell of it.