1- Dude blows himself up - The soldier who Flag tells to detinate the bomb BLOWS HIMSELF UP. If you order someone to kill themselves, do you really think they are going to just kill themselves.
2- Harley Throw gun to Deadshot who already has gun on his arm.
*- The Enchantress did not teleport. Instead of teleporting away, The Enchantress makes an illusion of Deadshot's daughter to try and stop him. She could have just teleported away.
*- Harley could I have just left, and would have. At the end when amanda waller shows up with the app on her phone and tells them they are going back to prison, Harley's device was disabled. So Harley could have just left. There was nothing holding her there.