Well considering one was trying to mimic the other...
I think that's just a matter of perspective. I've never had a problem with his performance (except maybe his YIPPEEE, that was kinda bad). To each his own on that one.
It varies for me for sure. His "I have brought, peace, justice, and security to my new Empire!" does fall pretty flat, I'll agree. Other times I think he does a fantastic job, like after the Tusken Massacre.
This is probably again a matter of perspective. I saw his performance in the prequels and then didn't see him in another role until I saw Captain America: The First Avenger for the first time. That's from 2004ish to 2011, and even then he didn't get much time to shine until Avengers in 2012, and then I really started to discover his other roles and how different Windu was from them. I think he plays it fine, but again, by experience with his acting may play a factor in that.
I won't. I don't subscribe to that theory. I can see the evidence that it could have been a thing, but it wasn't, so it doesn't matter (personally I don't think it was ever a thing anyway).
I wish she had fixed all the dialogue on Naboo following the arrival to the lake house. All of that needed a rewrite.
How was he an idiot? I see people say this and the usual response is "because he told Obi-Wan to train Darth Vader!", but that doesn't hold up. Hitler's parents didn't know how he would turn out. It's not really fair to criticize someone for something that they had zero idea would happen.
I'd love to see some different examples on this opinion.