You should be able to choose your vacation time. If you don't want to take 16 days off during the winter, don't. As long as your vacation days don't interfere with camp, your school shouldn't have a problem.
As per school hours - it can vary greatly by each school. Some schools make their teachers desk warm all day, others just half a day, and some teachers don't desk warm at all. It depends on the P and VP from each school.
Camp is normally 3 weeks, so that sounds about right. Teaching full days does not. If you teach over 22 hours a week, you are entitled to overtime. So if you are teaching more than 22 hours during camp, make sure you get your extra pay.
Just from personal experience, my first camp here was a district camp at my school, so I had to stay later everyday "organizing." If your is the district camp, this may be why. My next camp was much easier as it was just for my school.
(I'm also with SMOE. But really, it varies by school.)
If you have to be at school the whole time, but don't teach over your allotted teaching hours, there's not a whole lot you can do. You can ask your main CT to explain it better to you.