I go with Gamer here, Mace, Obi-Wan, Anakin and Yoda should cleary have a lot of synergy, being master-padawan for the middle two and Mace being padawan of Yoda, and Yoda being Yoda and holding his own vs Sidious, as seen (but lacking killer instinct, I guess because he felt most for the philosophy of always using the force in self defence, not aggressively - having beaten the foe is one thing, but is the killer blow then aggressive, or still defence?; the same is true,a s Gamer said, for Mace, I guess, at least to a lesser extent. It was almost as he sought acceptance from the only witness he had there before committing).
I didnt bother to check if there were martial arts specialists among the available Jedi on Corsucant (there are bound to be some who individually fight better than the mentioned three). In any case, it might not be a coincidence that both Yoda and Obi-Wan were away from Coruscant at the time (if memory serves right they were on Kashyyk and Utapau), its certainly possible Sidious manipulated it in that way (although we see that Yoda proactively says he will go to Kashyyk…still, with the attack on Kashyyk Sidious might have knbow that they send Yoda due to his special relations with the Wookies).
Yes, Sidious was able to hide himself, withdraw his force aura. Others could, Luke could it well I remember from the EU, as could his son. Coming back to an earlier post, Snoke must either be a grandmaster of that, or have no force ability at all. We will see.
Palpatines disfigurement I think quite clearly came from his own but reflected lightning. In any case changes should have been more stark after he revealed himself and overtly used his powers than the subtle manipulations during the CLone Wars. But I fully agree that he was likely always in full control vs Mace and needed it to look as dramatically as possible to effect the final click in Anakins already torn head. Which nicely worked. Had Windu taken Palpatine as prisoner, Anakin could have had continuous access with the hope to get the info out of Palpatine. All in all, I think the scene was ok. None of the Jedi really thought Palpatine would come at them with a red saber.
Generally speaking, though, there would be no movies without those totally illogical, totally absurd bad guy monologues to give the hero the chance to turn the table. Its incomprehensible to me that writers dont find better solutions that still keep up suspense. Ok, sure, in some cases its pathological for baddies, they need to show their supremacy over the opponent (Blofeld comes to mind, while Goldfinger had good reasons not to kill Bond in the last second), but for bad guys without that human weakness there are not many excuses.
I think the biggest disappointment for me was when Anakin so quickly gave in to Palpatine and killed Dooku. Yes, Anakin was conflicted and primed, but still.