Well, it depends on which specific comic series or storyline you're referring to. In some, he tragically meets his end, but in others, he survives and continues to play a crucial role.
Definitely not. T'Challa has always been depicted as a Black character in the comics, representing African heritage and culture. His ethnicity is an essential aspect of his character.
Well, in the comics, T'Challa had to overcome powerful villains, navigate political intrigues, and make tough decisions to protect his people and the legacy of Wakanda. There were times when he even lost his powers but always found a way to come back stronger.
The main reason could be that the grading process is subjective and might not accurately represent the true quality and worth of the comics. Also, it can cost a lot without guaranteeing a significant increase in the comic's value.