If we look at it from Toronto's perspective, how much bargaining power do they really have here? They have a manager who hasn't performed well (both in terms of record and clubhouse issues) on the last year of his contract. If they really valued Farrell like we seem to, they'd have offered him a contract extension by now. They haven't done this and by negotiating with the Red Sox are showing Farrell that he may not be in their long-term plans. They've often stated that they don't allow interviews and moves to a new team for lateral moves, yet they're talking with us about letting their head coach do just that, within the division, no less.
I agree with all the points you made about Toronto and Farrell, but a few additions. Simply because they have Farrell under contract, and they dont seem to be in a big rush to sort out their manager situation they can make the RedSox wait. Meanwhile, Ben went on record saying he didnt want the manager situation to take a long time to sort out, and the media is starting to put some heat on the RedSox to get it resolved. So, Toronto could basically make the RedSox wait and sweat to try to gain some leverage. At which point the RedSox could just say screw it and hire one of the guys they have interviewed. Basically, both sides have enough options to have a little game of chicken.