Craig Hockenberry wrote a Quick Look plug-in for .mobileprovision files (i.e. Provisioning Profiles). Hugely useful, because you can just select a provisioning profile and press space in Finder to see which UDIDs (devices) are included.
To debug provisioning profiles, don't let Xcode manage them. Instead when you need to run your app on a new device, take the following steps:
Now go to Xcode. Since version 6, you can view provisioning profiles by going to menu Xcode -> Preferences. In the Accounts tab, select your Apple ID on the left, select your team on the right and click View Details. The new profile should be there, or else you can click the refresh button. The expiration column should show the date as exactly one year later.
If you want the .ipa file, check out this answer on StackOverflow.