I have interest and quite a few kinds of esoteric alie civilization to experiment with.  Small housecat sized aliens (they aren't cat people.  That's just their size.  I mention this because I know there's people on this site whose idea of a space universe consists of space elves, furry aliens, greys and people who have a goofy face) with Escher inspired architecture perhaps?  

Some questions:

-When it comes to defining chemistry, does this essentially boil down to stating something like "they have a biochemistry suited for a chlorine heavy atmosphere" or "their DNA is right handed instead of left handed and have food that is universally toxic to humans" or "Living on the fringes of star systems, they utilize a liquid helium solvent"?  Do factors like what gas they breathe or if they like of chemosynthesis instead of photosynthetic agriculture factor into that section?

-Can it be assumed that life with earth-like conditions has edible food half the time (due to handedness)?  (Or basically aliens who have a chemical basis on a world like earth with water, oxygen producing autotrophs/Cyanobacteria & 'yellow' (as opposses to red from the plebeian (red dwarf) stars) light?). I ask this because I know there's people who believe that DNA languages will be as diverse as spoken or computer languages.  However space opera demands more personal interract with denizens of the galaxy and it's hard to have personal interaction when all the life is toxic to each other.  Not to mention space operas tend to be human-centric and chauvinism for our own biochemistry is pretty much inevitable (gives us more food options too). 

-What is the setup exactly?  Is this going to be like Babylon 5 with more alien denizens about the Galaxy or are things considerably more "anarchic" per say (i.e. No space UNs)?

-Is there a map?  If galactic which Galaxy map are we using?  I have a vector Galaxy map I can send to you if you have illustrator.

-What FTL system is involved?  Is it a worm hole network?  Is there hyperspace?  Or is it Star Trek warp drives?