My understanding is the national security law bans calling for democracy in Hong Kong worldwide. This means being outside of Hong Kong will not protect you if you later travel to Hong Kong. I understand someone calling for democracy in Hong Kong while in the United States, Europe, Africa, or anywhere else would be subject to arrest if they later traveled to Hong Kong.
Yup, especially for those extremely dissident towards the CCP. China would still try to extradite from neutral or China-friendly nations so that's another thing to be concerned about.
Still, this forum hasn't been used as a mouthpiece
yet[/] so nobody knows how safe this forum would be.