Don’t write any sensitive password down. For now anyway, I believe that the Fifth still protects memorized passwords. Also, techniques like OTR don’t involve a multi-instance user generated password. The key disappears after the communication is concluded.
For general use you can use OpenPGP with Tor and Torbirdy for secure and anonymous emailing. Having a privacy protecting off-shore email server doesn’t hurt.
“For now anyway, I believe that the Fifth still protects memorized passwords.”
Nope. Courts routinely order under penalty that passwords be revealed.
“Having a privacy protecting off-shore email server doesn’t hurt.”
The NSA is between you and that off-shore server.