WMUTeach

You have so many options but consider that your plan, and hopefully your grandson's plan, will be to cherish this quilt for his lifetime and beyond. So I would skip the temporary like his summer job. Stick with what is likely to last such as his passion about tech and HIS favorite colors. High school colors fade into the past very quickly as grads move into adult life or college or career. My feeling is if you try to fit in all of that you listed in your post YOU may not be pleased with the final result.

About the length, I made a quilt "River Trees" for a nephew that is 6' 5". I wish I could remember the final dimensions but alas, I can't. I did make it extra long and he mentioned specifically that he appreciated having the extra length. I think, I just guessed it and made it just about 6' so he could be covered from toes to neck and have a little snuggle space. Let us know what you decide. These quandaries are always fun to see when the final choice is made.

madamekelly

You could add a cardinal into his favorite color quilt just for the memories...

MadQuilter

I was part of a round robin group where one participant wanted us to make a quilt for her grandson who was into a variety of things that really didn't belong together. Supposedly he liked it. I thought it was a hot mess. Therefore I agree with those who suggest that you edit your options.