Ok, thanks for the clarifications. So a creature isn't a creature until it resolves, and therefore can't be targeted by a "damage creature" instant until it leaves the stack. To target it on the stack, it has to be a counterspell. Did I get that right?
like for instance say you play an oblivion ring. The opponent can respond by vapor snagging their 1 lone creature thus forcing you to target your own creature with the o-ring.