I have a very similar self-hosted Vaultwarden set up, for the same reasons.
My other concern, which may be unfounded is that Vaultwarden [1], which is an unofficial Rust rewrite, may also be developed to different, or lesser security standards than the official client. However I don't have any real reasons to suspect this.
Agreed. I know I'm taking it on faith that this implementation is robust and secure when it might not be. However, I feel okay about it knowing that it would be very difficult for anyone other than me to access this Docker instance in the first place. And if I'm outside my home network, I'm interacting with it via the VPN.
My other concern, which may be unfounded is that Vaultwarden [1], which is an unofficial Rust rewrite, may also be developed to different, or lesser security standards than the official client. However I don't have any real reasons to suspect this.
[1] https://github.com/dani-garcia/vaultwarden