Hey you guys, not sure if anyone has ever mentioned this.
There was never any point in sealing the Nine tails inside Naruto. (obviously apart from the fact that if not it would suck).
You can assume that a sealed creature will be released from its host when the host dies, because if not, the 4th would have sealed it within himself (like the 3rd did) and gotten rid of the 9 tails for good.
However, he didnt, he sealed it into Naruto.
Now, we know that the 9 tails does not enjoy being inside of Naruto because of the episode when Naruto speaks to the 9 tails just before he summons Gamabunta for the first time.
Therefore, why does the 9 tails lend Naruto his chakra? Surely, if the 9 tails wanted to escape he would not lend Naruto any chakra and Naruto would die in about one second (Haku, Neji, Gaara, etc..) and the 9 tails would be free again to break and kill stuff, which is what it wants to do.