Why couldn't the Dark Release: Inhaling Maw absorb Rasen Shuriken Technique ?
First of all, take all of this with a grain of salt. The movie is entirely filler, and was not explicitly explained anywhere.

When Hiroku tried to absorb and use the Rasenshuriken, the process of combining this specific nature with that specific shape was too hard for him. Remember that Naruto needs 2 additional clones and a significant amount of time to generate a rasenshuriken. When Hiroku tried, the technique blew up in his hand, and he didn't have the time to do anything else.

As for Hiroku disabling Naruto's chakra, remember that Naruto is the jinchuuriki of the Nine Tails, even if Hiroku could absorb such an incredible amount of chakra without being overwhelmed, The Nine Tails' hatred infused chakra is poisonous.

On a more "producer"ish note, Naruto had to win somehow...