When you press the edit button one of the options is Duplicate.
There is no 11/4, you'll have to write one bar in 6/4 and one in 5/4 or whatever other combination you prefer.
The Kindle has some minor noises in its audio playback. (any song, not only the 1200 jazz tunes)
The issue seems to be hardware related so there is nothing we can do.
Hopefully they won't prevent you from practicing.
Unfortunately I'm at a loss.
With Background Audio turned ON, it works for me and as I understand everybody else.
Try perhaps restarting your device.
Perhaps you have other apps open that are using the audio function?
Not sure how you 'lost' your playlists. There is currently no iCloud support in iReal b.
If you made a backup you can get all your playlists and songs from there.
If not you'll have to got the playlist here in the forums.
Not sure what Guitar Jack 2 is but if it's anything like iRig or Apogee Jam you should be able to make it work with iReal b.
Look in the settings of iReal b for Background Audio and next to it you'll see a button that will show detailed instructions.