While you can used the premium features without paying, I would strongly urge you to pay for a license anyway. It doesn't cost much and the Bitwarden folks are a small team doing a great product. I really like bitwarden_rs and wish the official server would adopt it or something similar. The official server is pretty darn heavy.
I work at Apple in engineering. User data privacy is a VERY big deal and something which is taken really seriously. It is not just marketing lip service.
Is Apple perfect? No, of course not. Are there things I think they should do better? Yes. E2E encryption with user keys stored in Secure Enclave, etc, etc. However, for Joe Consumer, I think they make the most secure, easiest to use platform.
In China, all your data belongs to China. That is simply the way it is if you choose to do business there. You might point fingers at Apple and other companies who operate there, but China is a huge market. The Chinese people know their data is all backdoored, so there is no coverup or obfuscation.
Functioning RF power harvesting MCUs have been demonstrated for a number of years now. Obviously there are challenges when the state-of-the-art is pushed forward, but the claims don't seem far fetched.
Yes, Bitwarden can be self-hosted. It is also a really nice secret management tool for humans, although it does have a CLI and API which can be used for machines.