Beginning:
This is now I manage my addons, with #1 and #2 being the most convenient.
1- I use something called Regshot. It is small, and portable, and stupid simple. It looks at registry settings AND directories you specify. It outputs simple to read Text or HTML file listing changes between now and when you run the program under scrutiny.
http://www.majorgeeks.com/RegShot_d965.html
This nice thing is that it doesn't install itself or anything. You can treat it as an add-on itself, unzip and copy. And it does nothing but a before and after list. This is how you use it.
a) Point it at the folder under examination.
b) Click "shot 1" It records the existing files and registry entries in a text/html file.
c) Install addon, run orbiter, do whatever.
d) Click "shot 2" and "compare".
Now you see all the changes your activities have caused both in the registry and your orbiter directory. It lists additions, deletions, and files that have changed during the monitoring period.
2- Alternatively you can just keep multiple orbiter installs around. Ready to restore instantly. Most of us do this. I always keep a base install for reference and testing. This is where you keep a "golden" copy of orbiter as a refernce for a filysync program. And use something like
http://freefilesync.sourceforge.net/ to instantly revert back after you're done testing.
I tend to install my add-ons in batches so before I begin I make sure I have a copy of a proven orbiter installation I can fall back on if something goes awry.
3- Let's say you have 2-year old orbiter install going. And you decide you no longer want X addon anymore. And X addon has been installed for quite some time already. And other addons after it. Well, the only solution I can immediately fathom is opening up the addon's zip file and manually deleting files one by one.
You can use a Duplicate Finder program here. What you do is point it at your current orbiter install. You then unpack the addon to a bogus temporary directory. Now point the dupefinder at this temporary directory. When you run the comparison it will highlight the duplicates in both folders - it should also give you the opportunity to delete these files from your orbiter install, as those would the "duplicate" files you no longer want.
This of course can break dependencies. In fact deleting files from any application and break stuff. But you're a good little boy, you made your backups, right?
Epilogue:
I've seen
complex and
bloated utilities to do tasks like this.
I know of no ready-made program that totally automates this process with one click. I've seen orbiter addon managers that have done all sorts of crazy things like keeping a database of changes or comparing your install against its own internal static database of popular addons. Others are more focused on testing the integrity of an addon's files and that they contain what orbiter requires; and only if something is out of order do they flag it.
IMHO none of these pre-made orbiter-specific "managers" will give you the versatility and ability to drill down into the folder structure as needed. Doing it by my methods will allow you to maintain complete situational awareness.
The techniques you'll learn by taking one of the above approaches will serve you well in future computing activities as well as get the job done. If there are other practical and simple suggestions, well, let's hear them!
http://www.easyduplicatefinder.com/screenshots.html --(payware)--
http://www.techsupportalert.com/best-free-duplicate-file-detector.htm --(freeware + payware)--
http://freefilesync.sourceforge.net/ --(freeware)-- and there are others like it.