This is pretty much as in MM6, except that the caster can only set or return to one beacon. If you cast the spell, you get the option to either set it or return to a previously memorised position, and that's pretty well it.Dragon Breath is a very good combat spell, but at your level, Energy Blast is probably a better spell to use. There are other, more important, spells than Dragon Breath. You try killing a Terminator with Dragon Breath, and you'll be toast. Implosion is the only spell that works well on them, and you really do need something to work well on them, believe me! If one of them hits you with a full blast, you end up with that character eradicated and all his equipment broken.
Detect monster - never used it. It probably displays a red dot somewhere on a display like the WizEye one.