I know how to change the variable, and that is all (besides the basics), also might be confusing, since I am not sure how to word it. 1: If a character has an item, but they'll probably never get it again, is there a way to remove it? For example: they picked up a flashlight, then later in, they drop it or lose it some other way and they have no way to get it back. Can the variable or changes to the score tab be removed instead of changing from a check to an X? 2: Is there a way to change the name without adding another variable? For example: they are in the foyer, then moved to the kitchen. Is there a way to change the location from foyer to kitchen without cluttering up the list under score or the awkward "Foyer - X"?
As far as i know you cannot completely remove a variable. But a variable can be set to "hidden". When you remove the Flashlight, i.e. set the variable to false, you can set the variable to "hidden" at the same time. The variable would still be there, but it would not be shown to the reader. For detailed explanation, see https://chyoa.com/chapter/Conditional-Branches.266625 and go to "6. visibility" Renaming a variable is afaik also not possible.
What do you want to achieve by using a boolean variable for the location? If I would like to track the location of the reader and use it in the chapter text, I'd rather use a (hidden) numerical variable, assign a number to each location and use them in the chapter text.
Your rooms situation would be the perfect use for THIS SUGGESTION from the site suggestions forum, if you add a like to it, it becomes more likely to be implemented.