If all you had to do was touch it and inject some chakra into it, it wouldn't be the disaster that it was when Madara and Tobi took control of it.
It does if all you care about is stuffing it into the statue and you're Tobi.
Step 1. Teleport someplace 100 miles away.
Step 2. Summon the Nine-tails.
Step 3. Sharingan him and seal him in the statue.
That is making a huge assumption. Tailed Beasts aren't Animal Summons. We don't know if the same rules apply to them.
It's also irrelevant because if there is a contract, Tobi already has it because he summoned the Nine-tails back when he fought the 4th.
I thought it was said by Diedara and Tobi after they defeated the 3-tails. But most of that arc was filler, so I'm not sure.
EDIT: Found it
I disagree.
Bee and Naruto aren't the same. Even though Bee controls Gyuki's power, his chakra cloak is exactly the same as every other Jinchuuriki's chakra cloak mode. Even though he supposedly has full control and cooperation, his cloak is still blood red, burns shit that it touches, and doesn't react to the wood style or give him the ability to sense hostility, just like Naruto's was before he defeated Kurama.
For whatever reason, Naruto's transformation is completely different from the other Jinchuuriki's(because he's the Six Path's reincarnation or some shit). And for whatever reason, now that they are teamed up, that transformation is being extended to Kurama's beast mode.