Ok, that's a lot to unpack.
On fur/skin coverage, wing colors, etc., etc., one issue is that I (and I'm not the only one) wig out when my description doesn't match the body/portrait so I end up manually assigning them all. So adding even more specific descriptions isn't a clear win. Good news though, there're folks on the discord working up a really cool sprites-based approach to auto-generating bodies and portraits (the art is a good ways along anyhow) which would make detailed descriptions, adding patterns and part coloring, etc. work splendidly with some work. I will try working on some of the things you bring up at some point (like why display skin color if they have fullbody fur?).
Another thing to consider is slave guild quests that look for certain colors need work too if you monkey with them a lot, depending.
There's a neat little game called Niche I got on Steam a long while ago. Basically you control a pack of animals with genetics (including fur patterns) and breed them to suit different environments/predators as you travel from one island to another. I have half a mind to go full on dominant/recessive genetic traits on Strive with dominant race controlling what genes actually get expressed (fur pattern never gets expressed on fur-less npcs for example), but that idea will probably get a low priority on the ever-growing list to be honest.
I'm aware of most of those bugs. I thought I'd fixed the last one with stats that balloon a long time ago. When did you DL?