you could encrypt the emails body with a gpg key that's going to expire soon.
Zoma
SearXNG or Startpage
I semi like and trust tuta but the Ui is shit and you cant use it with any other mail clients. After my subscription with tuta ends i think im going to use my domain on mailbox.org.
In my eyes keepassxc and bit warden are the only two options also there is IOS keepass clients.
In terms of use, librewolf feels exactly the same as firefox. I chose librewolf but zen is my 2nd pick try them both.
Love Mullvad and all their work but this one aint it, Im sticking with searxng.
This add-on may also ask to: Access your data for all websites
Sponsor Block works on front ends like Invidious.
One of my three extensions I use on my main profile It even works with Invidious! Ublock origin, NoScript and SponsorBlock in case you're wondering.
No solution will prevent people taking screenshots