Yes, all levels of the ring, in addition to a +1 magic attack bonus, give a +1 prayer bonus. And it is unlimited teleports, yes. With the ring given for completing the easy tasks of the achievement diary, there's a chance of making extra runes while runecrafting elemental runes. How many, I'm not sure. Might I also add that the cabbage patch teleport provides a quicker way of getting back and forth from the air altar. :)