Trash could use some improvements in Mac
Maybe someone has a concrete answer for you, but I'm curious about something. Not trying to nitpick...
Is there a reason there are things in your trash that you don't want deleted? If you are looking to keep them, maybe restore them to their location and delete them later?
Not trying to nitpick your style or how you do things. Whatever works for you...
I would have to agree.
The Trash is not someplace to store things or a place to keep things "in limbo" while you decide what to do with them. The only time you should put something in Trash is if you want to delete it and are ready to empty the Trash right afterwards.
Trash is trash. If you don't want to throw something out, archive it somewhere and dispose of it later.
Alternatively, you could always write an app that sort of decays or eats your trash over time. I don't get why you'd want to do that, but you can. You could also write what amounts to a trash picker so you could zap individual files that are in the trash.
If every item that was moved to the trash was something that people were sure that they wanted deleted, why have a trash in the first place?
The trash is there at least partly to act as a 'safeguard storage' in case, for example, someone changes their mind.
Many people use the trash for things that, at the time of deletion, they think they probably don't want (perhaps to the degree that the file(s) may seem to act as unnecessary clutter in their usual non-trash location(s) at the time) but which they aren't entirely certain that they will never need again. Sometimes, due to time restrictions, habits or methods, or something else, people use the trash as a temporary 'to confirm soon/later or when necessary' bin.
I never end up re-using probably >97% or so of the files that I move to the trash, but occasionally there has been an instance of re-usage.
Then again, I didn't realize until recently that trash data could get overridden when disk space is tight, and if that's true, I suppose that is a reason to be more wary of trash usage in that particular situation.
As for the original question, what I usually do to delete only particular file(s) in Mac OS is to move everything else in the trash to a temporary non-trash location, and then delete the relevant particular file(s).