Thanks guys for all your input. I've updated the guide to reflect these additional finds for both Chapter 2 and Chapter 3.
Since I didn't actually try them, and can't because I no longer own the game, they were listed as unverified but legit. Video links and quoted descriptions included.
Seeing how long this game has been out, I think that that may be wrapping up what can be duped in Dead Space 1.
The guide may or may not be updated again in the future. I honestly don't check the thread now but every couple of months. Family and all.
Again, the input and contributions were/are appreciated. If someone finds more stuff to add, post it!
Till next time...