I'm not sure I totally understand, but will try.
The piece that latches the cylinder that you say is tight...if your talking about the bolt that come up through the
frame and falls into the notch in the cylinder, this needs to be tight, it locks up your cylinder so it won't move or rotate when the gun goes off. The "stringed steel" you refer too, I take it you means the bolt spring and trigger spring, this is a spring that does more than one duty, one of which is the presure on the bolt, which I already mentioned locks your cylinder up tight. I would not loosen this spring, they make aftermarket springs that will take some presure off your trigger, but still have plenty for the bolt.
The piece you say that is rough cut and looks like a hacksaw butchered it, is the "hand" or some call it the the pawl, you are correct that this turns the cylinder. Yes, I've seen these pretty rough. You can smooth them up and take the burrs off, but you must read up a whole lot before you touch this piece so you don't mess up the timing of your gun. Other wise, this won't effect your gun as it is if it's timed OK, action may not be as smooth if it's rubbing on on the frame as it moves up is all.
I'm no gunsmith or anything like that, but had my single actions apart lots of times playing with them changing springs, a little smoothing up here and there....I sure hope I helped a little bit anyways.