I know i'm late but whatever.
What well-documented Sith do we know of who were not malevolent?
Well I don't think kreia could really be rated as malevolent, she nis a weir old women, who love to manipulate the others, but she never do anything *really* bad, she killed the three jedi masters? come on, they where arbitrarily trying to cut the exile connection to the force, without asking her opinion, and we know well how cruel it is, after knowing what it was for her the first time, so i think the jedi master were worst than kreia for killing them.
She maintained Hanraar alive? well maybe the reasons were not so good, but that's not an atrocity, the wookie is crazy, and she don't force him to be the exile slave, he just help him, and do two, or three thing to kreia, but for the rest he have some freedom.
And, also, kreia never support the dark side exile when he does the random cruel action, like killing anyone without any reason.
And she IS a Sith, and don't respect the sith code, as probably Revan, Then there is Visas, who also IS a Sith, and she might be a little disturbed, she's not really that bad, the poor girl, she have just seen all her planet being "killed" in front of her eyes, i guess we can understand that she get a little darky.
This argument is impractical and silly. I'm going to cite a real world example: the U.S. can't effectively fight al-Qaeda. Does that make America bad because we aren't perfect? It's a widely accepted fact that if anything in fiction is perfect, then the story wouldn't be good.
Not really, but for some people, the U.S aren't really good, starting a war on Afghanistan, because they don't tell where is a terrorist, of course ALL the country is responsible, and by the way,
Osama is still free, so they made the war for what? for anything.
Then Irak, atomic bomb? lol, there wasn't any, just the petrol
Then we have the medical assurances that just want to get all the money they can, often acting on a little "malevolant" way,
So, if you want to compare the jedi to the U.S, I think that then the jedi must really be a bunch of corrupt guys
. (I'm talking about the government, not the American people, and also talking about the jedi order, not the padawans, and all the jedi etc...)
For bad jedis we have worst that anything kreia or visas, could do, or many other siths:
During the final trials of the group's Padawans, the WatchCircle encountered a vision of their deaths and what they believed to be the return of the Sith. The WatchCircle as a result struck their Padawans down during their Knighting ceremony, save for the late Zayne Carrick. The WatchCircle then framed the murders on Carrick, which resulted in a galaxy-wide chase for the supposed fugitive.
The jedi masters killed all of their students because of a vision? where is the redemption? the "love"?
Also the jedi master who exiled the "exile" just because she fight for her beliefs, trying to protect the republic, while the council refused to act.
Without the fact that Revan became a dark lord, what revan, the exile, and the other jedis, have done, was the right choice, and they save the galaxy, and the jedis who stayed in a safe place, just have judged them.
Then you also have the conversation between yoda, mace windu, and obi wan, about the jedi order becoming arrogant, so are the guarantors of peace supposed to be selfish, over confident, and arrogant?
So no, the jedi order is not all white. Also cutting the children, for their families, because it can lead to the dark side? why don't they teach them to control their feeling instead of refusing them, Anakin wouldn't have fail if he could have trusted on the order to help him, without having to hide his relation with padme.
Jhonatan told the greatest power is "love", well the jedi aren't allowed to love. It's like the religions, at the beginning there are thing created for something good, but it start to become wrong with time, like for the Muslim who can't eat pig, well that was for health reasons, now "allah" will punish them for eating it. The catholic priest can't love like the jedi, and can't get married, and then we are surprised to see pedophile priests. The Christians aren't supposed to live in the luxury, well take a look at the Vatican.
I'm not saying the religions are bad, but what people do with it is often bad, and then it become corrupted, or have a bad interpretation, (commit suicide by crashing a plain on two towers, will lead you to the paradise), and in my opinion the jedi order is just like a religion, not bad in the depths but, in the reality it just don't go as well as it should.