I've been working on the lairs for several of the planets, plan on getting most if not all of the missing creatures added to world spawners for each planet. however the world spawners are limited to 2048 lairs for the entire planet, so once the planet has reached its lair cap it stops spawning more... some planets have multiple lair spawners one for world creatures and one for creatures/npc's in specific area's.
also if you would like to see more of the low level mobs around cities, I could use a little help with info on which mobs should spawn around which cities, If you feel like helping in that respect it would be much appreciated and would help to bring the immersion into the game that you are looking for.
if you decide to help, you can post a reply here https://www.swgemu.com/forums/showthread.php?t=79815 or create a mantis ticket in the SWGEmu TBD section. https://www.swgemu.com/bugs/view_all_bug_page.php A simple list like (city name: mob name, mob name, mob name, ... etc) would be helpful... the more detailed you can be the better.
Edit: forgot to mention, if you have any coding skills and feel like getting a dev environment set up you can help populate places also. the .lua files for screenplays and world spawners and such are really straight forward and not hard at all to work with. see the development section for more details.