Why are Imzigs and Clawdites NPC only? Clawdites I can understand somewhat because their shapeshifters. But why Imzigs?

Clawdites because of their shapeshifitng and people likely to RP insanely with it. Imzigs, likely because they are basically Klingons. And the devs don't want people using Klingon images for them.

I don't see whats stopping people now claiming they are Clawdite RP wise and just say they are shape-shifted to whatever race is on their profile when challenged on it. Same with images, I am sure it wouldn't be first time someone uses ST character image. Just seems rather pointless to me to limit those races, its not like ewoks that couldn't talk and had no technology to speak of.

It's because the clawdites abilities make it difficult to correctly implement them. The imzig were unpopular and as far as canon goes pretty much nonexistent, so the admins decided to phase them out.