1. All of that applies to pretty much every modern Kobo model.
2. If you read a couple books, and then for whatever reason decide to log out, the Kobo will delete all books associated with your account and will erase progress of any sideloaded books.
Bypassing registration is possible. But with no account, there's no guarantee that a new Kobo update won't come out and break your device.
The safest thing is to register normally and never log out. If you don't want to use your real email, a fake email is fine.
3. Not sure if this is a question, but if you want to patch,
here's the most recent thread.