In addition to being a repeated offender of many heinous crimes, could you see joker adding rape and cannibalism to that list?

Not really something in his MO imo

Yeah, I can see it happening

Emperor Joker was canon before the reboots.

And during Morrison's run of JLA he made a reference to eating a guy's tongue

Cannibalism is cool and all, but not rape.

I wouldn't doubt that he's done both before.

Cannibalism sure.

Rape is something I would see him ordering but not doing himself.

Once you cross the line into sex crimes the villain can’t really be marketable anymore in comics.

Joker has already raped before in Brian Azzarello's "Joker"

No

Yes, joker has no morals.

He stripped Barbara and paralyzed her but didnt rape her since Alan moore confirmed it never happened. He would probably never do it since that was a perfect opportunity