I think this can be solved using mention feature. Question can be asked as private and only mentioned people can have access to question. This functionality is not available yet but will think about it.

Simply change base page title to whatever you want. Since 2.4 ANSPRESS_TITLE is not required.

Oh ultimate member is not there only userpro and BP. Try select blank option in user profile and your previous hook will work.

Simply go to AnsPress option -> users and select Ultimate member as your profile:

You clicked submit button twice. Currently there is not any option to prevent this but will be added in upcoming version.

Good news is that, its possible in upcoming version. You can set individual page of each AnsPress page. It was in 2.4 task list but we shifted it to 2.4.x