1.no
2.i have alot of stages that come from the vault
3.i dont know just alot of them from the vault
4.yes i use psa's all of my characters have one whether the character is enhanced or a completly different moveset
this happened to me when i tryed to put a mensclrfacexxx the ones in menu inside common folder if you edited lets say sonic and put another textures and then rename the file it will freeze atleast for me it did maybe something like this happenede you inserted a menslrface that was renamed?