Thanks to the bonus material from Volumes 12 and 13 of the DBS manga, it's now seems clear that the language of the Galactic Patrol is stylized katakana. Well...maybe that was already clear to others, but now it's clear to me.
I spent some time cropping characters from the bonus pages and pasting them onto a katakana chart. Please feel free to check my work, I'm not positive on all of these.
Here are the charts:
Spoiler:
Spoiler:
-I had difficulty with Quoitur and Shimorekka's names and left out some of their characters.
-There are also characters for English letters and Arabic Numerals (OG73-1).
-There are also characters for another Japanese writing system that I have not made a chart for.
-I inferred the symbol for "Su" based on the "Zu" in Yuzun.
-Before these mugshots, based on the Jaco manga, I thought the character on Moro's belt might be the "A" sound (based on the scene where Jaco crash-lands on earth). Looking at the katakana, it doesn't seem like a good match. The symbol is present on the scale next the characters heights, so maybe someone can make sense of those characters.