Is it an insult to my US university to not walk in graduation? I will be graduating with a degree in Software Engineering. I have a 4.0 GPA at this institution (not counting the 3.85 GPA I transferred in with). The institution is awarding me Outstanding Scholar for my degree program/campus/year.

I am seriously considering not walking in graduation. Being on stage in front of people is not my definition of celebration, and I am not a fan of tradition unless there is a logical reason behind it. (I'm an INTJ personality type.)

For the outstanding scholar award, they will be giving me a certificate and honor cords at an awards banquet that is before graduation. Does that imply they expect me to walk? Is it an insult to not do so when they are giving me an award?

Actual diplomas will be mailed sometime after the ceremony in the summer. The ceremony doesn't cost anything to be a part of (other than the cost of getting a degree :). There are about 20 people graduating this year in my major. I have a sister graduating the same day in a city 8 hours away (and only an hour from home), so most parents/relatives will be at the other graduation anyway. As an alternative to the ceremony, I am thinking of writing thank you cards to the teachers and mentors who were influential in helping me get to this point.
If attending a graduation ceremony is not your cup of tea, you don't need to go.  Better to stay away than to go and be uncomfortable!

It would be considerate to let your department know that you won't be attending.  Some universities make more of a thing of graduation than others, so depending on the vibes at your school, you might want to have some travel plans that conflict with graduation day.

By the way, congrats!