Kindle Organization

Right now my Kindle app has every book in one long list. I can sort and search, but it's still a pain to find something. Especially since I'm very free about downloading a sample and then not getting around to reading it for months. I want folders:

New Books (Unread)
New Books (Partially read, might finish)
Comfort Reading
Writing Reference
Technical Reference
Other Read Books
Samples - Unread
Samples - Undecided

While I'm asking for some changes in the app, how about when I buy a book via the link at the end of the sample, it automatically deletes the sample and opens the book at the place where the sample ended?

Edit Apr 2015 - the second wish has been granted.