Correct. Spammers who link malware, inappropriate, or advertising sites mean that nobody can post external links. This is how Bnet forums have always worked. The newer version lets you eventually earn Trust Level 3 which grants some additional posting privileges assuming you don’t get suspended at any point. That is recent though and would not apply to a new poster.
Which was abused by people who sold accounts or stole accounts. Including former spouses/housemates/siblings.
Any changes to an account must be conducted by the registered account holder and you are now required to prove it. That means govt issued ID.
All IDs are deleted when the ticket is resolved. Blizzard has to follow the Personally Identifiable Information laws at both the Federal and CA state levels.
You can read all the details here Providing Government-Issued Identification - Blizzard Support
It covers what is accepted and how to submit it.