I didn't bother with Thousand Strikes at all (playing a strength based duel wielding warrior), though did max Mana Efficiency (more to help with summoning the creature early to mid game). One point in Mana Leech may work just as well, which I also did later in the game, when I had skill points to spare (I didn't have a problem running out of mana, just figured it might come in handy at some point).
