The following might help to avoid synchronization conflicts:
Allow offline changes only for processes if absolutely necessary (even if a feature is not available without a server connection).
Apply server rights for processes that are only available in online mode.
Unconditional Must Field (Mandatory Field) rights are applied on the client.
Apply unconditional Table rights by assigning processes that result in designer units not being shown if the user does not own that process.
You can revoke rights on the client for New and Edit by defining a Rights filter for an operation, e. g. when the user tries to add a record. In this case, the operation can only be carried out if the parent link record for New meets the filter criteria.