Depends. If your password manager is protected with a strong password and security key, it's probably low risk to store them together in most cases. And of course you use a good password manager (not lastpass).

Mullvad is by far the best. Sadly though, it doesn't work in China. That leaves Nord, Express, and Astrill. Not sure what the best is for that though. Usually I end up getting an international eSIM and using Mullvad on that when possible. Luckily, I find that when I don't need a VPN too much outside of using video platforms as pretty much most other things that I use in China just work without a VPN just fine anyways, and I'm much less worried about them than the so-called "Democratic" governments.

Vivaldi blogs with an email alias is the best that I have come up with.

Depends on the situation. GPG for email, OMEMO for XMPP, LUKS for full disk encryption, Cryptomator for cloud storage. Those are the main ones.