Sorry, I'm afraid we cannot accept or use unsolicited story ideas and game material. Furthermore, the plots and developments of the story are actually determined in-house well in advance.
That being said...
1. ComStar did slip its leash in the Dark Age (as indicated above); the Republic was able to slap them down again even in their weakened state, so far as we know.
2. ComStar would never stop being sneaky if it tried. But, frankly, nobody in the universe is capable of being anything BUT duplicitous and deceitful, so that just makes them normal.
3. Word of Blake is missing, as far as anyone knows. (But how MANY went missing only the upper leadership of the various Jihad-era allies, for fear of panic.) ComStar's disbanded military would have scrapped any Celestials, and the remainder captured at large were largely scrapped by the Republic or dismantled as a show of solidarity against the evils the WoB represented. Some spiritual successor designs appeared in the years since, but seeing a Celestial in the Dark Age means someone opted to keep a Mech captured in the Jihad despite the severe stigma that came with it. (Either way, neither the Com Guards nor the Word of Blake operate openly in the Dark Age, so large armies of either would be a complete scandal.)
4. There are other factions that have white schemes. Many DCMS regiments, for instance, use color schemes that are almost all white.
-