Are there VPN providers that do not require such KYC?
Yes. mullvadonion, but I wouldn't use it for a node because they don't have port forwarding anymore. You can tailscale through a VPS and njallaonion lets you rent it anon w/ bitcoin.
How can I fund my node with a part of my stack which might contain previously tainted coins due to having already been used for running an LN node.
Mix them. See: #296379 - I use something similar to this pattern too.
How to open channels in a private way? Taproot-related, etc?
I'm mostly using segwit only as last time I checked, most channels were still segwit - bigger anon set = better.
I used to use amongst others Wallet of Satoshi to move off-chain liquidity back on-chain. Is that also a possible attack vector in determining my node's identity?
Only if you also send back to your own LN node. What I've used in the past is submarine swap out -> wasabi -> new channel.
Yes. mullvad
onion, but I wouldn't use it for a node because they don't have port forwarding anymore. You can tailscale through a VPS and njallaonionlets you rent it anon w/ bitcoin.Mix them. See: #296379 - I use something similar to this pattern too.
I'm mostly using segwit only as last time I checked, most channels were still segwit - bigger anon set = better.
Only if you also send back to your own LN node. What I've used in the past is submarine swap out -> wasabi -> new channel.