Is it possible to share some subscriptions but not all or extra iCloud storage?

Sharing iCloud storage is optional. You can use other options in Family Sharing without sharing storage. Also see: Share iCloud+ with your family - Apple Support

Joyangz wrote:

What about News subscription? In particular, sharing with youths. Would parental control be applied to news articles automatically if channel selection is not supported? Thanks

Sorry, I don't know. Hopefully someone else here can help or you can use the Get Support at the top right of this page to contact Apple.