I am creating an IOS app where each user will have their own data that will not be shared with other users. Should I create a separate realm for each user? If I don't, and they only have permissions for their data will they still synch the entire shared realm even though they don't have access permissions for others data? Or will it just synch what they are permissioned for? If I create separate realms for each user is their any easy way to manage and look at size of individual realms. Realm studio has very minimal capabilities. Thanks.
Since the Realm Object Server only (currently) supports permissions on a per-Realm basis, you will need to create a separate Realm for each user if you don't want users to see each others' data.
If and when Realm Object Server does support object-level notifications, you could store multiple users' data in a single Realm and use partial synchronization to only sync down data pertinent to that specific user.
We are definitely interested in ways to improve Realm Studio; it will certainly be improved as we receive user feedback. If there are particular features you'd like to see please file an issue at our GitHub issue tracker.