The middle pics are a little out of focus but you might have spider mites. They will live on the underside of the leaf. The yellow spots you see could be from them. They feed on the leaf and create thing areas below that look like yellow spots from above. Get a 30x pocket microscope for $5 at your hydro store and check the underside of your leaves for tiny bugs that look like ticks. If you have them hen they are easy to get under control. If not then it could be 1 or 2 defficiences but I think it's mites.
Don't even worry about the yellowing on those lower fan leaves. Could be from slight overwatering but in all likelyhood it's just normal leaf degeneration. Your upper leaves all look healthy. You can cut those yellowing ones off and maybe wait a little longer between waterings.