Touch on a few things... 1. Juugo can transfer some of his abilities to Sasuke..since they are compatible (via curse mark) Juugo can possibly give Sasuke a more powerful curse mark. Juugo is the originator of Oro's curse mark and being that Juugo has already skin graphed Sasuke before he should be able to do it again and instruct Sasuke on how to draw out his clans power.
2. Kakashi at this point should have a kyuubi cloak just like everyone else... Naruto's last cloak was inferior to the cloak the alliance party has now. So Kakashi can use Kamui more effectively than before.
3. Mokuton has nothing to do with the Rinnegan....being that Madara stole Hashi's dna (Senju) he was able to combine that with his genetic makeup (uchiha) and ascend (combining the bloodline to become stronger). Madara can absorb Hashirama though how much of a boost will he get?