I needed to replace a leaking Frost Free Silcock. I opened the wall and un-screwed the old one. My questions is when I install the new one and lets say when tight it is not in the proper alignment (say rotated to the side) how much can I force tighten the silcock to bring it into alignment without taking a chance on damaging the soldered on copper female fitting?

First remove the sill cock, coat the threads with either Teflon tape (at least 4 wraps) or pipe joint compound. I prefer pipe joint compound. Reinstall until things begin to tighten up. When things begin to tighten position the spout downward. Then decide weather on not you think you can make another full turn. When you have so much resistance you don't think you can make another full turn, stop, turn on water and check for leaks. If you have a leak, put wrench on both the female adapter and the sill cock and make another full turn.