Having some items in you when you shouldn't, will block story progress. Cheats are very very not recommended unless you know what you're doing. (Well I wanted my old save game because I edited the old dll to not remove items when I gave stuff so it allowed me to play the game and see all the content in one playthrough. I can't even remember how much time I spent debugging it but I know enough to know I don't want to do that again lol
Saves are gone not sure how but I'll just have to play the game as the dev intended