Its nice to see newer shooters stepping up and wanting to design and set up stages....the effort will be appreciated by your local club memebers.
Looks like you have some good ideas, when designing stages, always remember rule 1.1.5 freestyle. And as in a previous post, design the stages as if they were going to be used in a level II match or higher. Just throwing this out there for you to consider, I would do away with the boxes, have barrels like you had in first pict, put a wall up between the barrels, and then use fault lines at left and right outer barrels, and maybe elevate one of the single barrels so they will have to shoot under it at the poppers...have start position be, "standing facing down range, with hands on "X's" of center wall...? just a thought to consider. I am not a fan of boxes..then you will have made it freestyle..