Apologies Jim, I didn't realize you were referring to only a first backup...
Personally I liked the old File Type and Creator system too... I never had an issue cleaning out my Mac running a Classic OS.
As soon as Spotlight debuted yeah, I banged my head and went looking for something else... enter EasyFind. The one and maybe only thing I liked on my PC way back when about a dozen years was the easier way to snuff out system stuff that wasn't needed anymore. "Registry" diving was facilitated by an app called "Regedit.exe". You looked up what you wanted... it showed you all the related keys... you checked them out and figured out easily enough which could go... and punt the thing. Does MacOS have an app like that for the System Folder? Nope.
Paddy, I don't have a problem with lack of space... my MBP has a 500GB SSD with around half left... however I detest clutter! Of course since it's just hanging around in some sensitive places it's my suspicion they can do no good there... but that may well be only me. It drives me insane some of things I've found really just sitting there.
Like Paddy I generally find that drag and drop installed apps don't usually leave nearly what an installer run app leaves around. It would be most helpful if those apps also provided an uninstaller... some do, but not all. Also if you are trying to uninstall Adobe STUFF like Adobe App Manager, Creative Suite stuff and so on, it will let you... in order to repair issues but you MUST reinstall the stupid things... for instance PSCS6 won't run unless it can access AAM to verify your license. OK, fair enough but I don't need it to uninstall or install PSCS6... there's a separate thing to do that. In the meantime all the thing is... is an insidious, overbearing marketing tool. Likewise iLife... I've deleted most of the apps... I have Photos along with it's library but I ignore that. I've never used that particular item... my graphic files, artwork and photos live in a folder I created. I direct iPad to look there for what to copy and no problem. The Music, Movies and Photos folders have only a few things in a self created folder labeled "MY... whatever stuff" Of course iTunes uses Music but you can put your library elsewhere if you like.
Anyway, thank you Paddy for the links... I'm off to read them!