While you can find more details elsewhere on thwack, the short answer is:
1) That kind of granularity is not easily available in NPM today (ie: version 10.3)
CAVEATE: you can glean *a little* information if you feel like scraping the IIS logs (%SystemDrive%\inetpub\logs\LogFiles\*).
2) User auditing in some form is included for NPM 10.4 (I haven't had a chance to play with the latest release candidate, so I can't personally attest to how much)
See here for more on 10.4
specifically item #8: "Support for audit trail"