Is this possible with Piwik?

I would be happy if somebody could give me some information about “Is that possible with Piwik or not” =)

  • Customize API (Turn on/off modules/feutures/stats of Piwik)
  • Create own modules for the API.
  • Nice performance of Piwik? (Please data, information, comparisons, etc)
  • Is integration of Piwik in existing systems easy?
  • What about updates/patches? Is it possible to save customized files and integrate it later without customizing again?
  • What about users and userrights? Can I create different users where every user only can see hiw own Piwikstatistic/information? Is Single Sign-On possible?
  • Is the interval of updating the Piwikstatistics custimizable (so no live statistic)?
  • What about the saving of the data? Is it possible to delete 3 years old data automaticly?
    Can I aggregate the whole statistic? For example: Number of total visitors of www.xyz.de in Germany, top 10 tags, etc.

Thanks for help =)

Short answer is yes.

Long answer would be more involved than I want to try via iPhone.