Some help with Mods

I am making little mini-mods to try to figure out how to make the last few levels possible with just the starting 6 (see Beyond Hero Mode ++ - How many stars is possible? for discussion) and I have a couple questions:

  1. Is it possible to not include all the files in the mod? I am only changing ONE file; I’d prefer if this was the only file in my mod. But, when I delete the other files, the game no longer recognizes that a mod is there.

  2. How can I make sure that importing a regular save into a mod will work? All I changed was the stats on a weapon, but the save does not import. EDIT: I’ve made a new mod, this time not changing ANYTHING. I still could not import. EDIT2: so importing just doesn’t work apparently. BUT, I added mod id=“TWOE_sucks” to the save file, and put it in the saves folder with an appropriate name, and voila, it works.