#1 Stewart is one of the best rim protectors in the league and you now have him playing on the perimeter, taking him away from his strength.
#2 Same as #1
#3 Duren gets cooked on the perimeter. That is why he guarded Josh Hart in the playoffs. He isn't much of an offensive threat.
If you want Turner, the answer is to move Duren. Turner is better on defense especially at the rim. He won't score as much probably but will provide spacing that Duren doesn't.