I'm not sure your inability to implement Kafka correctly because you didn't want to go through the proper channels is exactly a good reason to kickstart a new project around it...you just have to design your system to use it for what makes sense and deal with what doesn't. Putting PPI into it is madness.

touché

No user mgmt? Did Confluent keep this as a paid feature?

Yes, full namespace-based user management (SSO, LDAP etc) with lenses.io.

Strimzi worked out quite well for our POC. Any reasons to believe it will not in low traffic production? Pitfalls?

That's the problem. POC is easy. Once you start getting adoption is where the problems start and where you need enterprise-features: user access controls, auditing, SQL-based data observability for troubleshooting, monitoring, alerting, self-service admin, schema management etc etc.