This has enormous potential IMO. I think they should use the Black panther formula which was unapologetically black. Go straight up hardcore old-school martial arts, spy, mystical if the story calls for it. Don't try to white wash it. Go to China get the best choreographers, the fight choreography martial arts should be the best. Immerse us in the culture.
Shang Chi doesn't need to be able to meet the Guardians or Thor to be successful. He can be fully tied to MCU and maybe meet Black Widow on a mission in her movie. That would be a similar level character where it wouldn't be weird for them to be on screen together.