If you encrypt an iPhone backup on iTunes and then forget your password, you will not be able to restore from backup and your data will be unrecoverable. If you forget the password, you can continue to back up and use the device, however you will not be able to restore the encrypted backup to any device without the password. You do not need to enter the password for your backup each time you back up or sync.
If you cannot remember the password and want to start again, you can use a SmartKey iTunes Backup Password Recovery for iPhone to unlock iPhone backup password at first. Check out http://t.co/Rw8QSjrSsn for more details.
Yes you can. If you don't know the password or if you have forgotten the password, , you could access the phone with just a few button presses. You could try pressing the emergency call button at the unlock screen followed by two taps on the home button. This will take you to the favorite's page. You can use this page to access any emails, text messages or web favorites.