You're right, if you haven't heard me properly, don't take a guess at the clearance and tag confirm on at the end, a simple say again is all it takes. As for the "request" transmission. Don't bother with it for anything run of the mill like a level change, direct route etc. It's just a waste of time on the frequency. Although I will say that if you are going to make a request that involves me taking down notes (message to pass on to someone, details of medical emergency etc) then it might be worth teeing me up for that just to make sure I'm ready to copy.