I think neither Kyrie nor Durant cares what anyone thinks. I also think Kyrie really likes it in Boston and wants to be an all-time great in Boston.
I also think Durant could go one of two directions to end his career: 1) he could make a business decision where he should play next, where he could continue to develop his brand (Clippers, Nets, or Knicks), or 2) he could make a personal decision of where he feels like playing, and who he feels like playing with (Warriors, Celtics). Unfortunately, Golden State offers a bit of both.
Still, if Kyrie talked him into asking for a trade to Boston, on the threat he might completely walk away (leaving the Warriors with Curry, Thompson, and the fading careers of Green and Iggy), a Hayward for Durant trade makes a lot of sense for both teams. The Warriors cannot get a player anywhere close to Hayward's caliber in a different way. Even Brad Stevens wouldn't say no to that, as it would put Hayward is a great situation while significantly improving the Cs.
At that point, it makes sense to trade the farm for Davis. You prefer to keep Rozier as your backup guard. You also prefer to keep one of Smart or Brown. If you put Tatum, Brown, MLE, and Yabu on the table with your 3 draft picks, that gets it done. I think the Cs could keep Williams in that scenario.
Then the Cs have one guy in the height of his prime and two guys coming into their prime, to go with perfect role players (Horford, Baynes, Smart, Ojeleye), a good young big man (Williams), and a good sixth man (Rozier at 12-15 million a year).
That team could be the best team of all-time. I also think the personalities would fit together really well.
I wouldn't want to trade the farm for just Davis, but it's not up to me.