@meimeiriver You can save them.. er.. Look for the "Outfits" option in the "Wardrobe" section. It has a load / save in there.

Good question.
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I'm just starting out with Modding my game and wondered... Can I make my own interiors?.
So this is a great thread for me to follow.
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Then I wondered.. Can I make existing 'doors' open?.
A: There are doors that are just textures (on Liquor stores and such).. I'm guessing they cant be fiddled with, so some kind of "teleport" would be needed there.
B: There are some places where we have Glass doors, and a very basic interior, but you cant open the doors as "Any" of the players. I wondered if theres a way to break those and make them Openable to give us access inside.

Loads..
My own personal finding.....
After some search I found using "Menyoo" to change the model and then "Character Swap" to reset the Character Hash back to one of the three protagonists things went perfectly well.