What if we just have a simple system.

Guests -- Some kind Warrant's insignia
Members -- Some kind of Company grade officer's insignia
Moderators -- Some kind of Field grade insignia
Admin -- Some kind of General's insignia

The deal with O'brian's insignia is one of Trek's great mystories. However there is an episode in which he addressed as a Chief Petty Officer and in DS9, he insignia finally settles with SCPO.

Rather than use established insignia, why not create new ones based on something which is used internationally. I've been looking in this book of old WWII ranks used by every military officaially involved and it seems that just about every nation's Navy uses a system of different sized stripes. Why ...