So is it viable in a competitive list?

I really enjoy the R3 Astro + Freelance Slicer set up on Norra, but at the same cost as Redline it just isn't good enough right now. A bit cheaper and they could easily be a solid brawler for Rebs

Yes, just naked Norra is a good tank/brawler. You dont want her to be your scariest ship though. Fly her with Super Luke or Wedge to take aggro off her, giving her time to get in close. Toss Magva on her and she gets really scary at range 1. She already gets n evade, so 2 hits is basically 1 hit on her and you just gave her a lock on you.

Local player her flies her naked with Luke, Sabine, Blount