Yeah, there are a lot of issues that many of us in schools are experiencing. See this post for a collection of issues that we are hoping Apple will fix. You should add your issues to the list: https://discussions.apple.com/thread/5379636?tstart=0
Regarding your attempt to downgrade to 6.1.3... unfortunately Apple has stopped signing all versions of iOS 6 for iPad. So even with a complete wipe of an iOS 7 iPad in an attempt to restore an old iOS 6 encrypted backup, a restore via iTunes will force the device to check in with Apple and the latest version of iOS 7 will install on the iPad. I've also tried importing an old ipsw file for 6.1.3 into iTunes and into Apple Configurator to try and force loading iOS 6.1.3, but niether iTunes or Apple Configurator will install it.
And with Apple Configurator even if you were able to downgrade to AC v1.3, it doesn't work with iOS 7...only v1.4 works with iOS 7. So unfortunately once an iPad is updated to iOS 7 we are all forced to upgrade AC to v1.4.
As far as the downloading apps issue, the times that I have seen this are when the app isn't compatible with the iOS version on the iPad. For example, an iPad on iOS 6.1.3 trying to download an app that only works with iOS 7 will get the "Unable to download - Retry or Done" message. I wonder if the opposite is happening in your case... where an app isn't iOS 7 compatible yet and they are trying to download a version for iOS 6 or earlier. On top of that, I would recommend the student try a "reset" (different from restarting) on their iPads (Hold down on both the Sleep and Home buttons at the same time for about 10-15 seconds until the Apple Logo appears. When you see the Apple logo on the black screen, let go of the buttons. This “reset” fixes a lot of iPad issues).
Another possibility for this error could be due to your web filter settings. Did you attempt to block iOS updates with your web filter? You or your network engineer may have inadvertently blocked app installs. Check with your filter guy to see what the settings are.
Hope this helps. We're all struggling through this and feel your pain!! Good luck man.
I started my day with the exact same errors.
Now, we can't contact the servers. tracert shows the connection dropping after a Cogent node. This affects phobos.apple.com and albert.apple.com.
I'm wondering if the server availablility is related to the various errors from yesterday and today...