1) by design. It's more safe to put in the /body rather than HEAD
2) fallback + main code, we recommend before /body
3) one limitation is you can't use multiple trackers (ie. tracking in 2 piwik site on the same page) with async
2) fallback + main code, we recommend before /body
3) one limitation is you can't use multiple trackers (ie. tracking in 2 piwik site on the same page) with async