Yes, it’s secure and of course can be further secured by other services, like vpn and scanners and such. I front my stuff with Cloudflare certs on their free tier as well.

Just use complex passwords for the admin and logins. They also support two-factor authentication which is easy to setup.

I like Bitwarden because I can host my own server and control it all. Not sure if the other service does set-hosting. Maybe you can do the same with that?