I disagree with a few of your points.
- Do not write your password down on paper even if you cannot remember it. That is counter-intuitive and can result in your wallet getting hacked physically.
If you cannot write it down and cannot remember it, then what? No password at all? That's even worse. I have no problem with people writing down long and complex passwords - the key is to store that password safely. If you can store a seed phrase on paper, storing a password on paper is less risky, since the seed phrase is enough to compromise your coins on its own whereas with the password an attacker also needs access to your computer.
- Do not use advanced features like custom wordlist, BIP39 password, custom derivation path, Shamir's secret sharing, etc for your seed phrase. All of these are easy to screw up and will destroy your seed phrase copy as they can't possibly be remembered.
I assume by BIP39 password you mean extending your seed phrase with a passphrase. I would suggest everyone uses this. It is a fantastic tool.