Sorry this isn't a direct answer, but I think this might be helpful still...
A Philosophy towards 'tweaking':
It is fun to tweak things, but generally, the people who made a distribution or OS know what they are doing. Unless you have specific requirements, for example, a VPS with limited resources, you should just let it be. And if that is the case, you might want to look at a light version of the distribution, where many eyes have looked at it and figured out what can go.
This stuff doesn't really use a lot of resources, and is generally configured these days so they are not causing security holes. If they are causing security holes, updates on a good distribution are released fast and frequently. Going and tweaking is probably just going to screw up upgrades, or you are going to try to install something and it isn't going to work because of a tweak you did.
It is great to learn about what these users are for, and the curious attitude is a good one, but do it in a lab environment. :-)