I was just wondering if there are any places in the game where if you messed up earlier on in the game you are stuck and have to start over

I think there are spots like that. I haven't played this game in many years but I never finished it. "If" I recall correctly there was an item or something I needed that I had thrown away and couldn't find or something like that. I know this is vague and I could be wrong, but it does seem familiar.

Yes and no.

You can miss something and continue on even if it is a mask piece

the no part comes in because the game shouldn't let you into the final area until you at least have all the mask pieces. There are Teleport spots on all maps except for the final area and the Castle. You need to find them to use them other wise you have to backtrack through a whole area to get back to an entrance.