Welcome to slippery slope :) Rubi is a trans, BTW, not futa. But generally yes, overall body shape is much more essentional in gender perception than genitals.
Kui-tan for now. They are only furries in a game full of reptiles, amphibians, insects, arachnids, molluscs and humans with animal ears. And even they are favorite only due to lack of competitors.
She is in same condition hell Bess residing. There are lot of body TF options for her. She has clothes options. Her scenes are not parsed, they are literally hardcoded with ton of function calls. And due to engine specifics those functions are impossible to directly transfer. And I can't even...
There are Infection Terminal at Dr. Matt's lab with list of known infections and areas. Why not use it? Once you've got access to it - show possbile infected encounters list for area.
She is one of a massive characters. Her overall content amount is over megabyte of raw file size (not even including threesomes). But her pre-fertility content is fairly stateless, so it is possible.