He should have listened to execs.
Oh no lol.
Whiskey peak is primordial to understand the Barock Works underworkings and the undercover operation of Vivi and Little Garden is what ciments Usopp's will about pride and the reason he holds the line near Arubarna.
Those arcs needs to be in the beginning.
Ending with alabasta is more climactic and keeps the hype going into season 3.
This can also be done with a lighter season. In fact chances are that we will have a drum island that will have more conflict that in the manga. So that's most a good thing.
Cutting stuff doesnt mtter as long as you keep the core story and the tone.
There are things that are fundamental to the comprehension of the story and all those arcs have that.
I dont get with Oda picking the cast. Why an author chooses the cast. Oda doesnt know acting or anything like that. It seems weird to me. Just leave it to the director.
He knows his characters, if the work of an actor is close, there is no reason he shouldn't have a say. He is the best placed to understand how character should be played.
Also, there was no failure in his choices, so let's trust him with that.