this is currently not possible in ownCloud. You only get notifications for downloads if a "A public shared file or folder was downloaded" (see Personal settings page).
Yes and No. An internal user will normally use the desktop client which means that everything will be downloaded right away. In the audit log files of the Enterprise Edition will be additional information in this regards as its important for some compliant industries. Please help us to understand why you are looking for this information from an internal user.
The notifications are for complaince purposes, so we have a record of each user downloading a file when its released on a certain day. This log or email notification could be kept for record purposes. It would also be great if the owner or admin of the shared folder would be notified if one of the users uploaded a new file.
We plan to have a small group of users, maybe 50 max using the web based version only. No external link sharing without a login.