#2: probably not. Errors in a projection system (such as a camera or an enlarger) become exponentially more obvious the closer they get to the plane of focus, which in both cases is the film. If you see clearly defined dust or scratches, it's directly on the film. Clean it with a blower, or if it's really dirty just re-wash it. This is why dust on the front of your camera lens doesn't show up much (if at all) on film.

Also, keep those filters away from anything wet. Handle them by the edges. They're very fragile and somewhat expensive.