Some Q&A on Montessori high school...
1) Though I have an idea of how the course should go and anticipate some requests from students to adjust the curriculum, is there a case when the course is altered too often by the students? I just do not want students to request changes because they find certain modules /concepts difficult.
Yes. The goal is not to 'follow' every student whim or make every student follow every other student's whims, but rather to offer a variety of experiences that challenge a range of students. Student work must be challenges matched to their skills (if not, the result is either boredom or anxiety; read Flow). Your curriculum is a series of experiences within which students may have any number of choices. Avoiding work is not an option.
"All work is noble. The only ignoble thing is to not work." -Maria Montessori
3) How does the institution handle behavioral issues if they arise?
First, because of the nature of the school, there is a very low incidence of misbehavior. The sense of ownership and voice that students have at the school short-circuits a lot of behavior that might lead them to being excluded from such a community (that welcomes and values them). Beyond that, our work is to help students enjoy adolescence and prepare for adulthood. A part of each of those tasks is managing social relationships with other people. Another part is meeting expectations, both those that others have for us and those that we each have for ourselves.
4) Is it be possible to work with other Montessori high school faculty in order to know what has worked for them?
Yes. Some other Montessori high schools:
Great River School (St. Paul, MN)
Montessori High School at University Circle (Cleveland, OH)
Compass Montessori School (Golden, CO)
The Grove School (Redlands, CA)
School of the Woods–Woods High School (Houston, TX)
St. Stephen's Episcopal School (Houston, TX)