makes me sad it has to be done through SmashForge (which I cant use). if it has been possible to edit a serie icon through paint-net and injectpack like for the fighter's textures and food items, I would have made icons for each character who ever had a symbol to define it (like Bowser, Sheik, Palutena, Mario, ZSS, Link, Metaknight, Dedede..)
It's been a on-going issue lately with people's modpacks not loading at all from updated SDCaffiine method, and yet I'm not sure how to fix this issue. If you want a reference from a recent discussion about the same issue, you can go to this link here and see if it solves your issue.
As mentioned, it's collisions are the same as the Original Stage. I'm not sure if you mean the blast zones from Project M or not, but it wouldn't make it Wi-Fi Safe anymore. I'll see if I can take a look at it if I ever update the stage in the future.