So I found a really nice path to use, the only problem is a faint line keeps appearing when I walk around at the top of some of the pattern pieces. Is there anything you can do about this? Should I just scan again?
This action is perfectly normal. If it bothers you, you can try scanning again, but it's probably not worth it. I think you'll just have to accept it; whenever I'm in a Dream Town and they have paths, I see the faint outlines, so it can't be too bad, hopefully!
If it really disturbs you, though, I would recommend a nicer path.
I've never noticed this, unfortunately. I agree that you should maybe ignore it, try scanning it again, or just search for a different path if it really bothers you.