SPEED: For requests you mentioned this should be as low as possible. Can you give me an idea, I have no context?

This is hard for me to answer. It depends on how complex your site is, how many CSS files, how many feeds, how many JavaScript files, how many plugins.

Think of it relatively, if you have 100 and remove 20, that’s a 20% improvement.

If you have 10 and remove 2, that’s the same improvement. The context only matters in reducing speed.