I've run into this fun occurrence on more than one occasion while playing. The simple way that I've handled this in the past is that they do get the skill ranks and the languages, but the player has to fill them in on their character sheet in red colored pencil. If they take off the band of int, they keep these bonuses for 24 hours until the effect wears off, and then and only then can it be changed after being worn again for a full 24 hours/full nights rest (whichever happens first). So take the PC who wants to take off his band in the dungeon to drop their ranks in appraise and pick up ranks in disable device are out of luck in this instance unless the party wants to camp in the middle of a dungeon for 32-48 hours (and I would make them monster bait with wandering monsters).
And as far as languages that they can choose, I have stuck with languages that they could learn due to their race or the character's class at first level. Learning a archaic dead language that is only found in the most ancient of ruins in your campaign system should be something paid when the character levels up, not a nice side effect of an item. I envision the language acquisition aspect of gaining points of int along the lines of someone finally understanding how all that latin they learned from the nun's in elementary school finally makes sense in college. it wasn't that you didn't understand the latin, but you finally have a firm enough grasp of the latin to make jokes that others can't understand (also side note incase someone wants to flame me for using latin as my example, it is no longer a dead-language since words are actively being added to it once again).
