The jailbreak utility calls for the ambient light sensor and headphone port instances. It's part of the kernel exploit. Long story short, whenever you fiddle with the kernel, something funky will probably come up, in the case of Pangu, it would be the ambient light sensor and the headphone port. Another example of this IIRC was WAAAAAY back when @ih8sn0w was alpha testing/first compiled, he tweeted that his device was overheating drastically.
Nothing. You'll just receive updates on packages through Cydia that have been updated for 7.1.X support. Honestly speaking, if possible, I would downgrade my devices back to 7.0.6 and jailbreak using Evasi0n7, since most of the packages that I used on 7.0.6 are not compatible on 7.1+ at the moment.
False. Unless it's a plist mod or hard system mod, it won't be backed up. You'll need to use a backup tweak like PKGBackup. Alternatively, you can backup your installed packages manually into a list, then after the restore, place the backed up list into /var/mobile/, then restore that list of apps back. Make sure you're signed into your Cydia account before restoring the list or you'll get the HTTP 500 error.
To manually make the list, open up MobileTerminal or an SSH Terminal Client (PuTTy, Terminal, etc) on your computer. Login if you're using a computer.
Run the command dpkg --get-selections > installed-apps.txt
This will generate a text file in /var/mobile/ with a list of installed packages. I don't remember if it backs up the repos as well, but it does for packages. Save this text file onto your computer.
Restore your device, re-jailbreak, place the text file back into /var/mobile. Then run the following commands in order.
dpkg --set-selections < installed-apps.txt
In some occasions there may be a hiccup in the txt file, in which case, you can run
apt-get --fix-missing dselect-upgrade
TL;DR: Simple way to do it is to buy PKGBackup. Free/manual way uses Terminal Commands
How are you doing? Will this script work on the latest PanGu JB? I just bought a new Iphone 5s and first thing I will do is JB once I receive it. I would like to restore the cydia applications from my iphone 4s to the 5s using this script. I see you mentioned some applications you run do not work on the latest IOS/Pangu JB? Is there a list of Applications not supported yet IOS7.1.2? Also you mentioned an issue with SSH not working right away after the PanGu JB, is this still the case with the Pangu JB or have they fixed that?