Wait, with caution? Dude, I would do them all without the caution.
....Sadly, Jounouichi is still pretty much the same, but with boobs. As is Bakura. Kaiba's just going to have bigger bitch fits than he usually does as a man.
The only problem with genderswapping everyone and keeping Marik as having Yami Marik is that if Ishizu's a guy then that would make him the leader of the Tombkeepers because Marik and Ishizu's dad was a sexist traditionalist asshole (Though I guess they could've found another way for Yami Marik to manifest if they were creative enough). It was partly the trauma from having the hieroglyphs containing the directions for the Nameless Pharaoh to regain his lost memories carved into his back that caused Yami Marik to manifest to begin with after all.