Right, then Signal might not be the best option. The NSA can easily track who’s using Signal, and possibly do some traffic correlation to reveal who’s talking to who.
But to state that there is no privacy on Signal at all is a bit of a stretch.
Depends, who do you want to shield what information from? Signal knows all of their users’ phone numbers. You can hide it from other Signal users. All depends on your threat model.
Good for some use cases. Only if the Signal Foundation stays in the current track and it doesn’t go south like with Mozilla.
For a privacy chat group with random people, maybe another app would be a bit better.