Many programs run all the time on your PC and it's fine. Steam uses very little resources and is more than worth it IMO for the convenience of organizing and updating my games. I actively seek out Steam versions of games if I can find them.
I don't think you quite understand what I'm asking. I've no problem with steam, I have a great many steam games and it is, at times, quite useful. That said, the option to boot a game up when Steam isn't working or is having trouble switching to offline mode when the internet cuts out or I have no access is nice. It also proofs against *taps wood* steam failing.
As for Steamworks I'm not fully sure about the specifics but it's my understanding is that achievements are part of that? Paradox games have achievements (though only recently) but are only counted when running the game from the steam interface rather than directly from the .exe. Frankly though I'm not fully sure about it and, at any rate, that's all rather beside the point.