I disagree on multiple accounts.
Well, on her trail she said: "Of the love or hatred God has for the English, I know nothing, but I do know that they will all be thrown out of France, except those who die there."
This was a direct answer to "doesn't god love all his children, even the English" she also made several statements that leave no doubt that she hated the English.
Sith do not believe in some divine right to rule, except the right to rule for the strong.
Well they don't believe that the weak have any right to rule, but they do believe that their race has a manifest destiny (divine right by another name) to rule. And that any race strong enough to resist must be destroyed, thus the only strength they accept is their own.
Jedi and Sith both have Force visions. Jedi sometimes try to trigger visions through meditations. I don't know if some Jedi meditations include fasting, but I don't think it would be against the Jedi ways if they did.
I know one Sith (Lord Cylpho) who starved himself to bring himself close to death. He though that when death closes in, he would see visions of the future. I doubt that Joan Darc fasted to bring herself close to death, though
The Jedi would not object to mild fasting before meditation, nor would they recommend it either. However Joan Darc did starve herself nearly to death, frequently, it was one of the most commonly remarked upon things about her.
By the way, she started fasting after her visions started.
(While visions and hallucinations are not the same, they are pretty hard to distinguish. I'm pretty sure that there are many people in the Star Wars universe, people like Tharan Cedrax or Admiral Motti, who would call Force visions hallucinations.)
First her self enforced starvation came before her visions, her family said that she refused to eat years before she had "visions", I'm still refusing to call it fasting since she took it to a wholey unhealthy level. Secondly several of these visions reveal facts that were later disproven by her own countrymen, she even talked to a historical figure who didn't even exist. This means I have to call them Hallucinations, sorry. And Finally, I would call most of the visions people have had hallucinations, with very few exceptions, since most do not stand up to analysis of the known facts.