If you've already deleted the specific versions of the application, you can probably delete the matching pref folders. That being said, My usual rule for this is, if you have the room don't delete. The particular folders you are looking at aren't very space heavy, but if you HAVE already deleted the corresponding app version, they are superfluous. As far as app versions, I would keep the last one that can handle Type 1 fonts in case you need to deal with some old files that use them (I personally keep CC2021 v16 around for this purpose). And as @Robert at ID-Tasker suggests, always keep the second-latest around in case a newly released version is buggy.
I also keep a running CS6 (v8.0) around for the same PM reasons robert mentions, but you don't seem to have that folder, so you probably don't need to worry about that.