Bubbers, if you were the captain it was your leg. Anyway it was his technique that lead to the float not less flap. Also I believe flap 25 is normal on a 757.
Faster thrust response hey. What difference does a few percent here or there make? Measure it, if you can!
Windshear. No config changes. So you're happy to carry extra drag when you could do without are you!? Riiiiiiiight. The aircraft can also handle higher gust loads with less flap. Besides my FCOM says use flap 30 NOT 40.