Learn how to install addons manually. That way you will learn the structure of FS, and if addons get messed up, it will be easy to modify, or remove them.
Personally, I manually install everything. I think it's too risky to let a program automatically install and remove stuff from FS. Even if addons do come with an automatic installer, I always install to a dummy directory, and then manually install it from there. You never know what it might try to do...
Learn how to do it manually. It may take a little time, but you won't regret it in the long run
