What are some Illinois labor law technicalities?

[eorl]

I currently work a job in Illinois as a seventeen year old who gets paid 7.75 an hour in fast-food. The management is awful and pay are awful, but I want to keep the job as I have become friends with many of my coworkers and need the money.
1.) We use time cards that work on fifteen minute cycles. Basically, if a person works from 3:01 to 8:00 or from 3:00 to 7:59, that person will only be paid for 4 hrs and 45 minutes of work. Is this a legal way to pay employees?
2.) The job is not demanding enough to where we work continuously for 8 hour shifts, but we still are not given any technical breaks and one of the managers said we could be fired if we left our store went to a nearby store to get food. Is she allowed to not give us specific breaks because the job sometimes has 2-3 minutes of down time?
3.) If we did get breaks, would they be paid? The pay would also not accurately reflect the length of the break because of the 15 minute cycle on the time cards.
4.) The policy for registers that come up short is to have the employees who worked that shift pay the difference. The registers have been consistently short over the past few weeks each day and night. While I have not been asked to pay the difference at all yet, I have heard that previous managers required employees to pay for money that ended up being taken by one of the managers. Again, this has not yet been an issue for me, but I want to be prepared.
5.) Could I get fired if I complained (respectfully) to a manager about any of these points?

[marlan43]

Nothing illegal to report.