Screen savers are a throw-back to the old cathode ray tube type monitors of the last century. Modern flat-panel LED monitors of this century don't require screen savers (they are really just interesting eye candy).
Power saving features are not really necessary on the PI ( its a power hog, normally, but also nominally ) and what I mean by that is that for an iddy bitty computer it uses a lot of energy, but it uses nominal energy from a general computing standpoint (don't worry about it, it is very green)
Configure your monitor to go into power saving mode... most modern monitors made in this century (flat panel LED monitors do this automatically right out of the box).... again, don't worry about it.
Freundliche Grüße
