What I personally like about RxDB is that it also works completely offline. However, I don't really understand encryption: As far as I understood, it encrypts on the client side with the db passwort which is sent to the server.
Another issue is Authorization and Authentication, I could not find a good solution for me for CouchDB. Couchbase seems to have better solutions for this but the premium plan seems really expensive and as far as I understood you need a "server" and a "sync server" which don't have low system requirements, at least for me.
No you normally do not send the password to the server.
You can ask the user to enter the password when the application is openend.
Authentication is much easier when you use the GraphQL replication. There you are much more flexible on which data you return depending on which user is asking for it.
Another issue is Authorization and Authentication, I could not find a good solution for me for CouchDB. Couchbase seems to have better solutions for this but the premium plan seems really expensive and as far as I understood you need a "server" and a "sync server" which don't have low system requirements, at least for me.