Problem 2 - getting banned by any single random project for any reason, like CoC disagreement, a heated Rust discussion, any world politics views etc. would lead to a system-wide ban in all involved project. Kinda like getting a ban for a bad YT comment and then your email and files are blocked forever too.
The idea is nice, like many other social improvement ideas. The reality will 99% depend on the actual implementation and actual usage.