I do not know about the first question, but often, macro lenses will have the magnification listed on them in addition to focusing distances. The 15 and 30 sound like focusing distances. I am unsure of what the three-point-whatevers are. It is almost certainly not magnification, though, as the numbers are too high for the lens to achieve without additional extension (unless it is a very special lens).
As for the definition of a macro lens, it is a lens that allows 1:1 or greater magnification without the use of additional extension. However, it is often used to mean any lens that can focus more closely than most, even if it cannot achieve 1:1 magnification. The second use of it has become so common that you cannot assume a lens is capable of 1:1 magnification just because a manufacturer calls it a "macro" lens.