(3) Some people have suggested blackberry link backups might be useless since it requires a blackberry ID as well which needs to call home. I have a third party app called "iSkysoft Phone Transfer" which can open blackberry link backups - but what I found interesting is that it requires the blackberry ID password to open the backup but I can turn off wifi while doing it.
Hence, it's not calling home but is using a local password stored in the backup file.
Based on the above I think you can conclude that BlackBerry already built in redundancy in the case the servers are not available.
The phone will surely degrade when it comes to internet apps not working over time - but it will not brick.