Ok, first, about demonic phone calls via blood - when Abaddon "picked up," I was like, whoa, did Sam and Kevin realize that A. was going to kill somebody on the other end?
Now I'm stuck wondering how this "works". Abaddon heard Crowley's open call in "Sacrifice," although I doubt she was on the distribution list. Here, Crowley got put on hold and had to be patched through, and that was all very cute, but maybe that's what you've got to do if you want your call to be private - wait for the recipient to log in with their own bowl o'blood?
Second, I just kind of like how simply locking Crowley up, denying him his influence, isolating him, is doing far worse to him than killing of torturing him ever would have.
Third, at first I thought it was kind of awkward that Crowley rejected using Sam's blood for the ritual - it seemed like a bad attempt by the writers to keep him from realizing Zeke was there - but now I'm wondering if it was part of a longer term plan to mess with Kevin. I definitely think that Crowley was just getting started in 9x02 - Devil May Care. ("He's my new favourite toy. Wind him up, watch him go.")
ETA: For a lovely take on human!castiel working retail, read The Way Back by rainylemons.