> 1) Mining isn't required to use the network
I define participate as "be able to mine and use the network". You can't do both for free anymore with Bitcoin.
> 2) You don't have to pay any specific "club" to start mining. You need to be able to generate hashes efficiently, how you do that is up to you
Sorry, but it sounds like "In order to learn how to fly you just have to flap your hands more efficiently, how you do that is up to you"
> 3) It's still unrelated to what "permissionless" means in this case
From your definition "Permissionless Blockchains allow anyone to participate". Okay, you can sort of participate in tsunami by jumping in the sea, but do you really do?