1) this can be added
2) you can already achieve something similar, at least for usernames. You can add social users to a specific usergroup which you will deny to change username in the usergroup's permissions. Something similar for the email would be necessary but this will not be added to Flyover as it doesn't really fit into the plugin's scope
3) yet again you can customize the links how you want by tweaking your templates accordingly. You just have to add, for example, a link to register with Discord in your member_register template, or you can add the <flyover_login_box> variable there as well. Possibilities are endless.
Alright, also is there any way to automatically fill the CPF Username when the user link their account? to avoid the manually sync option? Thanks.
This is not possible at the moment, but can be added to future releases.
Thank you i will wait for the updates :)