I'm a subscriber and own a bunch of source books which I already have content sharing enabled for in the games I'm DMing for. I had two questions regarding the adventure books and sharing, however.

1. While I'm aware I can disable sharing of adventures to prevent my players having a sneaky peek at what is coming up, I didn't want to prevent them having access to the spells or any subclasses which might be included in those adventures. Is there a middle ground between locking the plot of the adventure, but letting them get to the things that add meaningful background to making their characters?
2. When I have content shared to players who have characters in a game campaign, is that content still open to them if they create a new character which isn't part of that said campaign? i.e. If 'Player A', who has an Artificer from the Eberron sourcebook I'm sharing with them, decides to tinkers with making new characters, do they need to be making said 'experimental' characters in our game lobby to have all the options unlocked?

Hope all that is clear! Thanks!

For point 1, that's how it currently works. Disabling the content from the content management menu prevents them from reading the compendium content (ie the adventure), but doesn't stop them accessing the character options through the character builder/sheet.

For point 2, you can only access shared content when making a character in the campaign that has content sharing enabled. In your example, yes, they will need to tinker with characters made in the campaign