Just a thought, if I upgrade from standard to premium, will any achievements gained while a standard member be taken into account when I become a premium member, or do I only get credit for achievements post-upgrade?
From the "How to play" page :-
Achievement badges won't be awarded retrospectively: if you go premium after a competition has finished you won't be awarded any of the badges you would have won for your performance in those stages. The only exception are the points award badges which are based on your overall cumulative score.
plenty of time yet though