I think so. You can talk to the managers about your hours. They will also call you about schedules sometimes or you can call them.
Yes, I will tell the jobs that I am busy this day and they will schedule me another day.
Yes they are very flexible if you have another job.
Yes, very flexible
I had another part-time job at one point while I worked at American Eagle Outfitters and they were accommodating to my schedule.
No. Must be 100% available even though you get 0-20hrs a week