Tactical errors of John McClane (DH1)

In the first Die Hard movie

The killing of the first guy (ho-ho-ho) should have been easy. The “that’s what my captain says” remark coupled with an elbow to the cheek should have been an easy shot from across the room. Instead he had the pleasure of crashing into drywall and falling down the stairs.

When he realized for sure that Bill Clay was Hans Gruber on the roof, he should have taken the shot immediately.

When he ran away from the raining glass and Hans and Karl’s bullets he forgot the detonators. He probably knew they were important to the terrorists’ activities.

When he was trying to get Al’s attention he apparently was shooting straight at him, since the flashers were being shot out and bullets were ricocheting off the car roof. What was this fictional character fictionally thinking?

In general, wouldn’t he have been better off killing the terrorists one by one as they went to look for their comrades? In the real world Hans probably would have started killing hostages one by one as soon as he knew there was a cop stalking his operatives in the building.