4) You can also parse MyClippings file with Kindle Mate:
http://kmate.me
I'm not sure if there is any programs that can extract information from files (modern equivalent of .mbp file) in .sdr folder. MyClippings file is not kept in sync with actual, current state of notes and highlights (= if you delete a note/highlights the "record" of it still remains in MyClippings).
5) You can have multiple dictionaries on your PW2 for the same language. There is a section in Settings where you choose primary dictionary for that language.