Herzog
Adventurer
Ok, Ill give you that a higher level spell or power should be able to duplicate several other powers or spells of a lower level. That does not negate the fact that it is still more powerfull than True Seeing (at it's starting, unaugmented level!) although at half the range. (True seeing still doesn't allow you to see creatures that are simply hidden) In addition, True Seeing requires a material component of 250 gp, while you get Touchsight for free.A 3rd-level power has the effects of two 2nd-level spells, plus some...yep, I'd say that's how the whole geometric power scale thingy is supposed to work--and if glitterdust doesn't fit your needs, see invisibility is a 2nd-level spell too, with a duration 10 times as long as touchsight. Augment the power to 11 PP (equivalent to a 6th-level power) and you can do some of the same things as true seeing at a shorter range.
Only solid objects block line of effect-like a wall. No matter how dense the undergrowth becomes, it still doesn't block line of effect.Regarding dense undergrowth, keep in mind that the power doesn't let you ignore line of effect--if it's dense enough that you feel a creature shouldn't be able to be detected in it, chances are it's dense enough to block line of effect.