^^^
This second suggestion does happen, the attacker shoots , collects the rebound, shoots again. I don't know if I've seen other players follow up though, which happens IRL, GK fumbles a save, or punches when he should grab, ball goes to a dangerous areas...
Edit: I wouldn't mind seeing some punishment for issuing GK for set pieces... that's a pretty desperate move
The rebound thing happens off the 'keeper, and I've benefitted from it sometimes - but not if the shot hits the post, in my experience...