Hi Katrina, there already is a Grammar section, still being built! As for spelling I don't know of any plans yet, but as KA is a dynamic web site with new material being added to it every year it's not impossible that you'll see it here eventually.

2) sounds like a great idea, and thank you for sharing!

You are not the only one wishing they were able to get diplomas from KA.  There are some issues there with identification that are common to all online learning institutions which have not been solved in a satisfactory way yet: How do you know it's the right person doing the typing and the watching? How do you prevent cheating? Once those problems have been solved in a manner which satisfies the Universities and school authorities your idea would also seem to be well aligned with Mr. Khan's idea of free education for all.

(volunteer Star guide)