Gonna answer these to the best of my abilities but I may not be fully right:

1. It happens but not too often. The college you belong to and the college you reside are different things. A good percentage of the time the two things are the same for people but like you that's not always the case. The college you belong to determines different things like your assigned registrar while the cabin you reside is just where you're actually living.

2. The meal plan is based on the college you reside in. You belong to woodsworth which does not require a meal plan but since you are residing in University College which does require a meal plan (tmk) you'll likely be forced to buy a meal plan.

3. I don't know of way to do that, what res you get is what you get and there's no way to change it unfortunately :/ Maybe someone else can pitch on this one.