I found the double tap method as Isaac calls it to work best for the entire game, not just these bonus ones. Also, I found using my left thumb as the reload tap worked better than using my left pointer finger. May just be preference though.
The minigames can easily be done later once you are good with the shooting controls. I did them all right away, and found the dove one hard. Now, when playing through the game, I never miss a dove, or any of the mini games really.
Also, I personally never had any issues with the jug one. I literally completed that on my first try, and I think have never had a hit detection issue on that level .