Some people will think this is stupid and unnecessary, but if you do, please don't comment because this isn't a topic I want to debate whether it fits, I want to talk about how best to do it.
bad publicity? You mean by being inclusive. I guess for the hate crowd that would be bad publicity, anyway that isn't something I wanted to discuss.
Not to mention I'm kinda unenthused about having to hear the average stereotypical gamer dude's thoughts and opinions on transgender people in their video games. (I'd love to be proven wrong though!)
These were a bit unnecessary, as people here will most likely discuss the limitations of modding, without being distracted by such discussions, except for you.
Here how it can be done, in a "fake" way.
Get a program that can write glyphs, which is what single letters/icons are called in fonts. Open the included ttf font and replace the Venus/Female and Mars/Male symbol with something you like, for example the female/male/trans symbol you posted. Now each ingame creature, regardless of gender, has this icon. Ignore that it can be male or female, just make both the same, and you now have a "gender" symbol.
Make a lot of castes, assign MALE and FEMALE tags in a 50/50 ratio.
Use insolors string dump replacer (
http://www.bay12forums.com/smf/index.php?topic=108721.0) to replace all mentions of "male" and "female", either be deleting them or adding something gender neutral. Replace all his and hes and hers and shes with he/she and him/her, to keep them gender neutral. Edit:
Download link for string dump 40.19 ready to be used.
Now make a new bodypart, call it "gender". Or sex. Or whatever word you like to use for it.
Now make new color descriptors, calling them "male", "female", "trans", "male sex-changed female", "cis" "whatever".
Assign these new bodyparts. Doesnt have to be something like an arm or a head, but more like a throat or gizzard or hair. Something that cant be hit by weapons and doesnt rot, etc, so it never shows up in any screens beside the description. It should work exactly like "his hair is brown.". "Her skin is tan." ... just that yours will read "His/Her gender is cis-male." "His/Her gender is female transgender male."
Now make assign these bodyparts with the fitting descriptor to each caste. Once for the officially MALE and once for the officially FEMALE castes. For realisms sake I'd leave out male-descriptions for officially FEMALE tagged castes, because otherwise they might give birth after marriage. Otherwise you can go wild, and make the wildest gender/sex combos. You also get lesbian, homo, hetero and all other combinations of marriages, although depending on how you set it up, the lesbians might still give birth.