Can I place personal tools in top right (as in Vector or Monobook), not in Sidebar?
Yes, it's possible, but requires some tweaking in the skin file CavendishMW.php. I might create an alternative version of the skin with the personal tools in the top right. Not now though, I'm very busy at the moment.
By the way, there is another Cavendish skin available which has this feature. See http://www.mediawiki.org/wiki/Manual:Gallery_of_user_styles#Cavendish