One of the great things about 6 was no "standby". That's nothing but a complete waste of time. I don't know if policies have changed, but 3 was notorious for putting studs on standby.
In the end, just suck it up and do your best. You have no control over where you go, and worrying about it will only make things worse for you. Do your best and don't sweat your grades and NSS, it will all work out in the end. It's been my experience that selection is usually based more on timing than grades anyway.