If a course at your high school was UC Honors designated, but the UC app doesn’t reflect that, it could have affected your UC weighted GPA, which could have affected how your app was evaluated. That would be something to bring up if you are making an appeal.
As for your other questions,
- I believe “has international experience” is asking whether you attended a school in another country. There’s a question on the UC app about that.
- I think “support program” would refer to where you “indicate if you’re interested in the Educational Opportunity Program (EOP), which provides support services when you’re at UC.” You don’t need to disclose on the UC app whether you had an IEP or 504 at your high school.