I have some problems setting up the mail accounts with mail.app on my MBP.
The thing is that mail.app screws up my gmail inbox, by creating unwanted labels and keeping copies.
The inbox looks like this:

And I have some questions:
1. How to stop mail.app from creating labels?
2. How to stop mail.app from showing counters of SPAM and TRASH folders.
3. How to delete or mark as spam in mail.app and make it go to SPAM and TRASH folder in Gmail.