I am curious to know how much information other school's enter in a Student Attribute as well as the reciprocal Relationship attribute. 

Specifically, when entering authorized person's to pickup a student, do you also in the authorized person (Relationship) attribute enter the student as someone they are authorized to pick up.  It seems redundant to me to do it that way and can be very time cosuming if the parent has a lot of carpool participants.

We use Student Attributes quite a bit - but not for authorizing pick up.  We enter all sports the students participates in attributes, all clubs, honor societies, etc.  We also use it to indicate if students want to in a student directory, be in a car pool list, if their parents are alumni, and probably several other things I am forgetting. 

To authorize who can pick up, what we do is list them as individuals and we check "emergency contact".  We never check the parents as "emergency contact", only all the relationships that are allowed to be pick up the student. 

For reciprical, we will have father and then reciprocal would be son or daughter.  It feels like overkill when you have to type it in, but later when you need to pull information you see you need it.  The reciprocal for the emergency contacts might be the same as the relationship, eg., Neighbor or Family Friend.