Are you kidding me YES XD Nothing stopping them from doing the poses, but being unhappy about it XD Nothing stopping you from taking artistic liberties with the picture No one is going to judge you if it's not exactly the same. The main goal is the challenge to replicate the feel of the original image If I did people that didn't want to do the pose, I'd just give them a reason to be there so they're still in character
If you don't finish ideas, there is the consideration of just stopping the idea and coming back later and reusing the idea in a way that does inspire you. It's better to draw 10 ideas, and only finish 5 than it is to only draw 5 ideas, and be forced to finish all of them, like them or not. I found that my ideas got better if I allowed myself to not want to progress a picture further Sometimes the first idea isn't the one that is the best.
True. I am getting better at finishing things, but there are still some that sit around. I have a lot of paintings sitting around unfinished due I don't have the space to finish them.