Should just be a check option in the keybinds page. Make sure “character specific keybinds” is unchecked and then /reload. As far as I know, they are stored server-side.
As for the other options, no, you’ll need to set them on a per character basis. Things like turning on autoloot and turning off personal resources under your character’s feet are ones I have to set each time I make a new alt and I’m pretty sure they are stored+defaulted server-side, until a local change is made.
After a new character has been created and loaded into, you’ll have a folder and some files associated with that character in the /WTF/accountname/servername/charactername folder. The one you’d be looking for would be config-cache.wtf and you could probably manually copy+paste over your master character’s config to it. If you really refuse to use a simple addon for things, you could write a simple .bat or .py script to handle it. Other than that, any locally saved per-character variables would likely be located in that folder as well.