Cydia has nothing to do with the app store. It is run by a someone else. You may not verify your apple id with Cydia. It is just not possible.
No. Cydia tweaks is fully updated for the ios 7 for apple.
yes
An apple worm is a larva belonging to the codling moth, Latin name Cydia pomonella.
no
It's available for all apple devices except macs. (yes, there is for Apple tv)
they re Apple signatures from current or previous firmwares that you save with cydia
nope, u get the ipsw from apple, the legal distributor
allows 3rd party applications, also considered hacks by some, that enable functionality Apple doesn't allow on the iOS platform
they re Apple signatures from current or previous firmwares that you save with cydia
Cydia itself is considered to be safe but apps that you may download via Cydia will not have been checked (as they are from Apple's App Store) and so may compromise your personal information without your knowledge.
From the Apple app store or from Installous via Cydia.