CONGRATULATIONS on your achievement!
The only way (now) to get a class deleted is to replace the same class as EC won't let you stack up unnecessary classes (like in the good ol' days.) The only way to get a "C" or "B" tossed out is to replace it with the same class. Having said that... Make a final push and go for it!
As far as your graduation, you are crazy not to go especially since you only live about 5 hours away. It's in July and your daughter's ceremony is next week. I don't think it would detract from it, but rather add to the festivities all summer
If I didn't live on the West coast I would so be there but the 10 hour flights and the time isn't doable. Being 5 hours away you have a great opportunity.
Best of luck in all of your pursuits and way to go again.