Has anybody figured out, yet, why the Words in the (Power) group cost less than the base cost for spells of their level? For example, the Kill Word costs 24, yet it's a 9th-level Word, so you wouldn't be able to use it in a spell costing less than 32 points. But its Target Restriction is Single only, and the Single Target Word costs 0, so there's 8 points you're not spending there.
And yes, certainly you could add another Effect to such a Power Word spell, but why do Wordcasters get to make spells that are clearly better than the basic Power Word spells of core PF, then? If the point of setting the Power Word levels equal to the core spells that match them, was to balance them with the core spells, then why not set the costs equal to force the issue?