Should I use a package manager? I want to keep keep track of which files belong to which application, so that when I uninstall an application, I can be sure all of its files are gone, including configuration files, dependencies it might have installed, etc.


There are GUI applications that can be downloaded and just dragged and dropped into the Applications folder, like GIMP or TextMate. Is this the best way to install those apps, or should I use a package manager for them? Can I be sure that these applications do not install anything outside of their Application folder? Is deleting an app from the Application folder a "clean" uninstall?
There are applications such as Python which come with an installer (.mpkg). Is using that installer the best way to install these apps, or should I use a package manager for them? How do I find out which files these installers touched, and how would I undo everything that installer does in a clean way?


I'm interested in some kind of best practices, for which using a package manager is recommended, and when just installing it like said above is "clean" enough.
Since I do not install and uninstall multitude of apps daily, I prefer to use something that will not constantly burden my system like a package manager may do.

I use a very simple but very effective app called AppCleaner (what a name), that is only running when I ask for it.



It will find all the related files to a given app and show them to me before I hit delete. 

It allows the deselection of drivers ect. if you want to keep them for some reason.