I agree with you; I'm not some crazy kookoo yelling about judgement day on the corner, this is just some 'food for thought' discussion.

For the first part of your argument, the issues I mention do not affect the security of the product (signal) itself, they would just enable spooks to more easily sidestep the whole product.

I also do not have anything against using the phone number as uid, it's 'good enough' for most people, and it greatly simplifies things. It is a very sensible default. What I'm questioning is the hardline stance of not allowing anything else at all - while 90% of people would be fine with signal as is, why not give the remaining 10% of us kookoos a bit more freedom?

As for the Sybil attack, does signal allow users not in your 'buddy list' to send you messages?