To save time:

No underage/loli. Things like braces, cheerleaders, school girl outfits, and pigtails are fine (and common porn niches), but I will not draw blatantly underage content, or anything skirting it.

No scat/ws. Just no.

Those are my two major red lines.

And no, gutting isn't all I do. Stabbing, shooting, strangling, asphyx, etc. - I'm open to most things. Ask me.