You haven't missed out on any achievements if you don't' send your score. If you uncover something during it or find a ghost, they count as soon as you uncover/find them.

I'll look into adding it to the page that you need 1 shovel point to open the chest, because that isn't a glitch.

def check how many ghosts you had before and after. I just tested it by playing easy and found one ghost and just closed out of my game (didn't let it end, etc) and checked my achievement and it registered the one!