titanmelon said:

1. How many mutually-exclusive body style tags do we (officially) have?

From the top of my head:

• anthro
• feral
• human
• humanoid
• semi-anthro (ambiguous)

• chakat
• taur

Chakat are taur, they're even implicated to it.

Others I've been curious about:

• alien
• animal_humanoid
• monster

- Alien is ambiguous and usually tagged by outside knowledge. We'll probably have to disambiguate it sooner or later. And it's not mutually exclusive with anything except human. Most aliens are humanoid, but some are animal-like enough to be tagged as anthros. Such as some Krogans. There's also some taurs, etc. Not sure if there's any feral aliens.
- Monster is for creatures that look 'monstrous', regardless of the body type. It's under reconstruction, needs massive re-organization and cleaning. But for now, it's the best tag we have for various abominations (post #153313) that don't fit anywhere else.
- Animal_humanoid is a humanoid subtag.

There's a tag group:body type wiki, which is very well-written, and I wonder how much of it is 'official'?

Most of it, I hope, since I got an 'okay' from the administration for creating it. Though that was an early version and didn't include all the subcategories.