Problem solved, grievance averted. A solution is found that both suits the administration and happens to be somewhat logical. What a relief.
My new schedule:

7:30 HS supervision, attendance, email, mail.
8:05 Travel to MS
8:30 7th grd orch
8th grd orch
6th grd begin/intermed.
10:43 MS plan
11:20 7th grd orch (short period)

11:50 Travel to HS/Lunch

12:10 HS Set-up/Plan
12:43 Intermediate orch
String orch
2:30 End of school

Hang out til 4ish doing plan for next day

2:45-3:30 Tuesday after school: Remix