1.) Enemies drop 1*(random number between 1 and 3) shards during their death, but you can still shoot them while they are dying. so empty as many shards into an enemy before they expire.

2. Smashers (last enemy encountered) always push you clockwise. To evade the damaging red hit-box either get out of the purple pushing area by retreating to the center of the stage (be it traditionally or using the edge mirror mechanic), or move counter clockwise around the stage.