'Restore from files targeted as hub': is the capability that controls "where" one HUB-backup can be restored. I guess it will be granted at category level or so, to create "arena" categories where teachers can restore courses from hubs and, later, import from them into their real courses or so.
'Restore from files targeted as import': is the capability that controls "where" one EXPORT-backup can be restored. It's completely analogous to the HUB example above. The only difference is that the "import" functionality is, really one backup + one restore executed a the same time. So the user must have moodle/backup:backuptargetimport capabilty in the courses he is granted to "pick from" (source courses) and moodle/restore:restoretargetimport in the courses he is granted to "add contents" (target courses).
'Allowed to roll activity configuration dates on restore': yes it's the capability that controls the ability to roll dates on restore.
Of course, feel 100% free to reword EVERYTHING!
Thanks and ciao