Isn't Wasabi supposed to be a completely non-custodial wallet?
It is completely non-custodial wallet, in the sense that you have access to the private keys and that it's open-source.
That's what I thought. IIRC, it is a bip39 compatible HD wallet, correct?
Does the pool just send those funds back to the address from whence it came?
The coordinator probably just refuses to include you to the CoinJoin.
This is what I don't get. I should download the new version and play around with it so I can become more familiar with the way it works. Don't you have to send a transaction to the Join Coordinator server, and if so and it's rejected, what happens to that transaction?