Well you should get paid for every minute you spend doing their work. that means if you gotta come in and see what their schedule cause they can't plan properly, then you should atleast get paid for show up time.

If you are part or flex time...I believe it is legal. States differ, however.
Contact your supervisor / boss and calmly explain your need to plan your life.
You could call in for the schedule, though, couldn't you? Though that requires trusting the person giving you the schedule...

I'm marked as 30 hours a week, flex time. I get maybe half of that per pay period. But yeah, the scheduling guy is doing this to the entire 100+ employee department.

I'd say bring it up to management this is inefficient. While he has to keep you under so many hours to not give you too much time, they should treat their employees' lives with more respect. While things come up they'd need to call someone in for, that does not excuse poor scheduling.

I will say I would not want the scheduler's job, though. It isn't easy.

I don't believe there is anything illegal going on... high annoying, probably, yea, illegal, I wouldn't say so. (Not where I come from, which is a right to work state, anyway). If you find you have to travel over there to get your schedule, then you might want to check and see if there is a website they upload the info to you can log onto or if you can call in and find out if it's your day off when schedules go out. I haven't been quite in that boat myself, my jobs have always pretty well had set schedules.