^ Again it would imply nothing as a full blown war was declared and Karin must have been in on some of the plans, as Tobi intended to sync Sasuke with the Mazo, he must have revealed something. He explicitly said that she 'knows too much' and is a liability, meaning, something concerning war must have been in her knowledge.
Sasuke left before he could get any tailed beast. Those could be given to him, to built up his power to acquire eight or nine tails. This doesn't mean, that he would give one away to Sasuke and reduce Mazo's power. Again, he was trying to gain his trust for the aforementioned reasons. That Bijuu could have been absorbed again without any trouble. I am unsure why is it a factor here.