I know that Intelligent Items are considered creatures for at least some purposes, but I have heard that they don’t possess skills or feats from Hit Dice, on account of having no Hit Dice. Do the rules indicate anywhere that intelligent items should, in fact, have no racial Hit Dice in the construct type? The reason I would assume that they do is because the DMG (here quoted from the SRD) says:
Intelligent items can actually be considered creatures because they have Intelligence, Wisdom, and Charisma scores. Treat them as constructs.
And, while the game never tells you how many hit dice intelligent items have, creatures do always have Hit Dice, as far as I’m aware.