Diorama room? (basically a room that has areas styled after each chapter)

Sounds interesting… imma try to keep the general idea in mind when adding a new area at some point.

It would be nice to have an option where we can add our own screenshots for one or two photo frames via replacing one or two photos [that would be] included in the mod's folder.

I do like having screenshots based on past events with others, but being able to have a few that the player could have just for them (just client side) would help make it feel a little more chill.

That's a really neat idea yea. Should be easy to do too.
I could prolly have the middle floor's wall photos names just in the description so you can asset replace them client side.

Actually since all the screenshot names are really similar it'd be easy to replace ANY screenshot, so i may as well entirely allow that possibility.

It's not as easy as dragging a picture into the mod folder though obviously, you'd have to make an asset replacement mod that directly addresses the path of each screenshot that's cooked into the map.