HDX authorised devices muddle

[cybmole]

i am trying to get to grips with the new prime music service, whcih is like wading through treacle.

I have found my list of " authorised devices" whcih have helpful mames like My PC" , My 2nd PC", "my Kindle"... and I dond't see how / where to edit those.

I am pretty sure, that the " my kindle" which is authorised to play music is my fire tablet, not my voyage e-reader. going by the authorised date, but names assigned elsewhere do not seem to work here.
i.e. a while back I made sure that the tablet was called kindle fir, and the new voyage was called kindle, so that I could see where I was sending books.

I also think that any PC which upgraded to win 10 this week has to be authorised again. I finally got prime music playing on this PC but I see a PC on the device list that was authorised today, so I am unsure if its safe to delete the PCs that were authorised earlier this year ?

so has anyone figured out how to consistently name devices across all amazon services so that shopping in app store say, has same device options as shopping in Kindle store, and in authorise for prime videos, authorise for prime music....