[Brumos RSR]

Must be a US thing, at least it not something I have been aware of 

1.No
2. I wouldn't know, but I suspect some due to actual new cars having a backlog.
3. I wouldn't know, I used one a while back as My son dinged my door with his on the driveway on a windy day, prices were pretty reasonable I thought, more so as he paid them 
4. I don't think so.

Sorry, i've not been much help there 

No worries as your answers made it tons of fun to read.  Tatters06, thank you for the insight to UK coverage.  Our liability minimums here vary from state to state to state and can be as low as 25k US and 5K for medical.  Pricing is all over the board as well,as service from the provider, which means you usually get what you pay for.  
We have huge supply chain issues for used cars, new cars and OEM parts which some insurance carriers require on a repair which may have a car sitting for months waiting on a headlamp for example creating a nasty pricing spiral as cars sit waiting for parts and insurance companies will not pay until the car is complete. 

OK back to slot cars