I noticed an odd bit of wording in the text describing the "third" use of the halfling good luck charm.
If you read the first 5 sentences of the paragraph, it appears to me to be clear and complete: a halfling can spend his own luck on behalf of an ally.
And then there's an additional sentence: "The halfling's Luck modifier can apply to any roll made by an ally: attack rolls, damage rolls, saves, spell checks, thief skills, and so on."
To me, this last sentence is entirely extraneous if it is referring to the halfling spending luck on an ally's behalf. We already know that expended luck can apply to all of those kinds of rolls.
But the sentence doesn't say, "Luck expended can apply to ..." It says, "The halfling's Luck modifier."
Read literally, the sentence means that, in addition to being able to expend luck on an ally's behalf, the halfling can actually add his Luck modifier to allies' rolls at will. That would mean that a party that included a halfling with a Luck score of 18 would have a permanent +3 to all their rolls unless the halfling spent some of his luck and reduced his current Luck so that his modifier dropped.
Am I being crazy to even consider the possibility that this literal interpretation is what the rule intends?
I agree, the text could have been worded a little better to avoid the possibility that someone could misinterpret the rules this way, but as I've stated elsewhere I think that anytime you can interpret the letter of the rules two ways, and one way makes sense and the other doesn't, you should always go with the way that makes sense. The notion of adding the halflings's Luck modifier to everyone's rolls is ridiculous, so I would assume that by "Modifier" the writier intended to mean "Expended Luck".