Thanks for responding, to clarify the following is true:
Since chat bots are account level, only admins can install the bots
Other questions:
2. What impact if any All users in account & Only users installed the app has on the apps?
3. Is there any way for a non-admin to install a chat bot at all and only receive chat messages for the user that installed the app?
Good question, this will trigger the respective webhook notification for either all users on the Zoom Account with the Chatbot App installed, or just for the user who installed the app.
Either an Admin, or a user who has the respective account permissions can install the Chatbot app.
Once the Chatbot is installed, you can simply only send Chat Messages to the person you choose.