I'm a long time pump user (type 1, just like you). I'm going to answer these in the order you asked them.
1. Pumps have sport guard cases that can protect it during sports. However, it's recommended that during contact sports you take it off.
2. Pumps can be disconnected without removing the infusion set. The sets have a "tail"...a few inches of tubing that comes from the actual cannula that's in your abdomen. The pump can easily disconnect from a juncture.
3. Pumps have belt clips that just clip to the waist of whatever you're wearing. They are about the size of a pager so it shouldn't get in the way. They look like pagers (mine is often mistaken for one). You can tuck the tubing into a pocket or under the waist of your clothes. That's what I do.
4. Some pumps are waterproof, others are water resistant and others can survive an accidental dunk. When I shower, I disconnect my pump while I'm in there. Mine is not water proof. I disconnect it to swim or shower.
5. As for wearing the pump at school, make sure the school knows that it is a pump and not a pager. Many schools do not allow students to carry cells or pagers with them while in class.
6. You will have to check your sugar even more frequently...about 6-8 times a day. You will have to be very vigilant about your sugar levels.
7. If you get a pump, you will have to attend a pump training course to learn how to use it. I strongly suggest that one or BOTH of your parents go with you. The company of whatever pump you choose will provide you with information on the class.
8. The infusion set should be changed every 3 days. It really doesn't hurt...you can get an injector device that just shoots it in. The needle will be removed...only the plastic cannula stays in your skin. It will take a few tries to get the hang of it.
9. Sleeping with a pump takes a little getting used to. You can clip it to your PJs or undewear or just put it next to you in the bed (that's what I do).
If there is anything else I can help you with, feel free to email me through Y Answers. If you have any other questions or whatever, I'll get back to you.
Good luck with whatever you decide.