If for example you're currently super admin in any groups, (as a premium) then you downgrade to basic level, while you will remain as SA you won't have any of the previous tools. You'll be able to post but won't be able to do anything with team matches or vote chess. You'd need to add someone else within the group who is still premium to do this for you.
If you join a bunch of tournaments as a premium then drop to basic you should still remain in those tournaments.
if you downgrade your membership from premium to basic (free) account, how does it affect your current status? like ongoing tournaments, being group admins, etc... anyone knows? thanks.