I think you have a good chance anywhere. Interesting background, in-depth ECs.
I feel like you shouldn’t worry too much about the 91. As long as you are able to articulate yourself well in interviews you’ll be fine. Also I don’t think it would hurt mentioning the reason for your grades in MP1.
Since you are in 9th grade now, I recommend applying as a repeat Sophmore, as Junior year spots and FA are probably very limited at most boarding schools.