nice bag o' rat'ing.
Anyway, A, there's things which require a target. when an ability says "target" and has something actually there like creature, enemy, ally, then that thing only works with a target that is indicated as valid by its own ruling.
I'd even go so far as to rule that powers which have to target an individual creature, as opposed to a square, object ( someone said air is an object, and thus cannot be a valid form for a "creature" targeted ability ), or general direction, automatically fail if used against anything that isnt a creature, such as a 'guess' as to where a creature is invisible standing or some such (and there is in fact no creature there). In fact, I'd give them this option if they whine: Either accept it fails, or we'll go ahead and talk about how you go off balance and fall prone on your face for fully swinging to hit an expected target. maybe 2 damage for the faceplant, and woe betide the individual swinging like this one square from a precipice.
Now, about the use of a targeted power to teleport any time. Consider this: If a person can teleport at any time, what about some impassible terrain? Suppose its either a deep ravine or some slope thats too high up to be reached without some tough work, or through a locked set of bars? what if theres many solutions to all of these? Destruction of terrain, going around, keys, forcing open, sending up a high acrobatic person to the point to get a rope tied off for the others to ascend, etc etc? All of these problems will be solved by a simple *poof* teleport. That seems to degrade gameplay, not enhance it.
About the targeting and teleporting as they work together. you teleport adjacent to the target, right? No target, nothing to teleport adjacent to. it is the power's design of using a target as a focusing point that it would fail.
Narrativism comes into play when you allow the Warlock to sacrifice little children who aren't a threat in order to buff up before the combat begins.