itunes import settings?

Ok for some reason I'm going crazy here. I was fiddling around with itunes import settings and I forgot something. Those settings only affect when I am importing CD's into itunes right? They do not affect any songs that have been already imported from the original CD and then imported into my computer without the CD. Since I do not have some of my original CD's with me I only have the songs on my ext. hd, do those import settings in itunes affect the quality of those songs that will be imported from my ex.t hd?

Not at all if they are already MP3.
It only affects new imports from CD as you said.