There's no automatic way to grant access only to your followers.
The alternative is to create a project with restricted access and distribute keys manually. You can revoke these keys if you want to block someone's access, but you'll have to manage them manually.
Regarding your second question, the staff doesn't usually answer the forum (sometimes the admin answers a question or two, but it's very unlikely), so no one could tell you if there are plans for that, but I doubt it. If you read the forum or the suggestions section, you'll see that many requests are more urgent or affect more people and haven't been implemented for years, so I don't think something like what you're asking for is a priority or on the staff's agenda.
EDIT:
I almost forgot, but in restricted mode you also have the option to set a password to limit access.