Do all Jedi have darkside moments?

I fully agree about Mace. I think he was justified in what he was going to do because Sidious proved how dangerous he was. He was not an unarmed enemy, he was fully armed and would have made it very hard to get him back to the temple alive.

 

Jedi are human beings (or sentient non-humans), and they struggle with emotions just like all of us do. The whole point of the Jedi Code is to discipline themselves to use the Force ethically. They strive to avoid conflicts of interest, or situations in which they are tempted to use the Force for self-gratification.

That said, in fights, yes they get angry. By the time they are fighting, they are already a step past where they try to remain. The lightsaber battles are great action sequences, they make good movies - but from the Jedi point-of-view, if you are fighting a battle, something has gone wrong.

Consider Dooku to Anakin: "You have hate, you have anger, but you don't use them." (my emphasis) I don't think any of our Jedi are drawing on their hate or anger, or the dark side of the Force, in their conflicts. Do they have passionate moments? Yes. But they are trained from childhood to resist drawing upon those emotions for power.