Rockstar have said there is no way you can change your character's features, sex etc. Once you have created it. That is why they advise people to take their time and think wisely when creating a character.
Like previous posters you will have to delete your character and start again.
The main protagonist, Arthur Morgan starts out as an asshole. That can take some getting used to after the lovable rogue that John Marston was in the first RDR. Also the main plot was John Marston hunting down his old gang to find redemption. In RDR2 the gang is out robbing and killing for money. Because Dutch "HAS A PLAN!"
The sand pit is bigger with more content. Better side stories and voice acting than the first game. This game is slow burning as the story unfolds. I loved the first game too. Yeah move on pilgrim. This game is not for you.
Well I have noticed some bugs are still there. I got kicked out of a session twice. My horse seems sluggish to get going at the start of a mission. I haven't notice changes with my character but I spent most of my time on horseback.
I got Buelle as Arthur, when I completed missions with Hamish as a gift. When Arthur died, Buelle did too sadly. I loved that horse.
You could try with John and see if that stranger mission spawns. But I'm thinking it will not spawn a second time. You would have to start a new game. Wait till you are playing as John then try.
I agree the prices for guns are ridiculous they should be more realistic, to reflect the era. Same for camp equipment. I paid 80 bucks for a sheet of cloth (lean to). Crazy. Rockstar will have to make changes to the economy otherwise RDO will end up a turkey.