Everything's looking peak in this Pizza Tower mod... aside for Snick being scrapped (I assume at least), considering that he was playable in SAGE 2019 Demo and had cameos all over the game's development including the final game itself. Everything else is perfectly fit, including your original take on Fake Peppino - screw that rivalry, you're cooking great.
As for Stick... I think he definitely deserves his boss fight being brought back and remade since he was the fourth boss before Fake Peppino took his place. He wasn't planned to be playable in the main game dev history, afaik.