Yes zocker, it is possible to miss, that is why the laser sight and long barrel is mandatory on the 870. If you don't have them the cross-hairs are too wide for the pellets to be concentrated enough to kill reliably and the range is short for the one-hit kill area.
You are a hit-marker machine or an air gun without the attachments. I had a hard time with the cherry blossom challenge so I can gold it.
Yes it dose take skill to use the shotgun, one is to make sure you are in an area that your shotgun is not effective at, but also making sure you move around so you can control each engagement. You really want to say away from multiple targets because you don't have the fire rate to take on a number of enemies at the same time, an SMG can take multiple enemies on easily. You have to play to the gun's strengths and stay away from the weaknesses.