NO and NO.
They already had enough scoring w/ Curry, Iggy, Klay, Barbosa, etc. It never works when you bring in a guy who main weapon is his scoring. Durant isn't a Lebron James. He is not a great two-way player.
Defense
Barnes better than Durant
Ezeli/Speight better than West and Varejao (s of himself after all those injuries).
Bogut way better than Zaza
Barbosa, well GS didn't get anyone to remotely place him so the just forces Iggy and Klay to play more minutes (not good in the long run).
Offense
Durant much better than Barnes
Ezeli/Speight combo still slightly better than old man West and injured riddled Varejo
Bogut a wash to Zaza w/ the edge going to Bogut for Offensive Rebound putbacks
Barbosa - nobody on their bench is even close right now to Barbosa.
All GS did, got much weaker defensively and are now forcing their starters to player more minutes.
They are worse off. Only so many shots in a game. And to top it off, GS signs the very player that Kawhi as pretty much owned the past two years.