These all seem like pretty typical signs of transness to me, but imo that doesn’t really mean a lot because feelings around transness vary quite a bit from person to person. I think since you are already questioning, the better way to see if it is for you is to experiment with yourself a little. If you have people you can trust to be cool, maybe explain your feelings to them and ask them to refer to you with a different name or pronouns in private, just as a test run. Or maybe try the same but by making an account online somewhere, if anonymity is a concern. If you’ve got the money, maybe pick out an outfit that you can wear for yourself. Or maybe try painting your nails or getting them done. If these things make you happy, that’s probably a good sign to continue, and if not, then you can just change back, no harm done.
Both RDR and this DLC kinda stink in my opinion, but I like that it’s coming to PC so people can still access it in the future if they want. Unfortunately, it’s got the same nasty DRM RDR2 has, and that took years to crack, so piracy may be off the table.