Don't blame the victim.

 It turns out the derailleur may have been the victim of axle failure. I cannot see a combination of it and a spoke having sufficient strength to snap an axel.
So that and entire new back wheel.

Buy a Bike it's cheeper than a car and keeps you fit.

I have owned such reliable cars as a Triumph Spitfire 1500. A legendary unreliable car from a legendary unreliable manufacturer in a legendary unreliable era.

I spent less time fixing that than I have my 2nd hand Viking Urban X. In about 2 years I have had to replace the bottom bracket bearing twice, the front and rear brake calipers, the rear set of cogs again twice and the chain twice.  

 Nearly forgot the pedals have had to be changed too.

I do about 30/35 miles a week, 99% on roads. I've put on 10lbs.

Today coming back from the office the rear derailleur disassembled itself.

So that is another Amazon order in.

I'll bet when the new set is fitted, the annoying squeak under load is still there.