SM
Fair enough. I personally prefer Obi as is, but if you can swing it as a storyteller, I'll be very impressed.
I'll certainly be trying, though I don't plan on bending much of Obi-Wan's personality beyond increasing his patience and understanding of Anakin. I feel that preserving the original intent of Obi-Wan, a former maverick among Jedi, one who challenged the ancient precepts of the institution before becoming Lawful Good or whatever, would help strengthen the bond between teacher and pupil. Thematically, it would show that Obi-Wan is somewhat prepared for Anakin's intractable ways, that there is a shot that Anakin might pull out of this rebel streak all right, that he's not doomed from the beginning.
It'll add another dimension of Obi-Wan beyond the mere knight in shining armor we're led to believe he always was. I'm going to emphasize the experience and occasionally Machiavellian side to the wily Jedi.
SM
The institution is notorious for its corruption though. EU especially concentrates on it, but even Padme and Anakin discuss how the Senate is inefficient and morally bankrupt.
My countless enlightening chats with Lucius have really matured my perception of stories. For example, what we know of Senate corruption in the films falls squarely under a rather notorious trope indicative of low quality writing. We know that the Senate is corrupt because we are told it is, but we don't see it much beyond Palpatine.
This is lazy and ultimately damaging in that it places far too much blame/credit for the Republic's downfall squarely on Palpatine's shoulders. The reality of it is that while Palpatine is clearly an astute behaviorist and beneficiary of a genius-level intellect, he hasn't the time to induce corruption ex nihilo on that magnitude. It's important that we see that the Senate is flawed and imperfect; that the Separatists' concerns are legitimate so that we do not operate under the delusion that one side is "good" and the other is "evil", which is a mentality the films and most of the CW3D show propagate.
In fact, consider the immortal line in the ROTS opening crawl: "There are heroes on both sides. Evil is everywhere." This, coupled with the recent CW3D episodes introducing the audience to legitimately sympathetic and thoroughly well-intentioned Separatists, leads me to believe that George didn't want us to believe CIS = bad, Republic = good.
As far as I'm concerned (and my views are echoed by Dave Filoni), there is only one true evil in the universe at this time and that is Palpatine. All the rest are capable of evil, brutal acts, but there is noble intent or a greater good behind it. Palpatine, on the other hand, is an unrepentant narcissist and psychopath concerned only for himself.
So, the long and short of it is that I feel we must see as many flaws in the Senate as we do the Separatists.
Ares
Hmmm... Maybe I was wrong but didn't he intend to spread his Dark Empire across the entire galaxy?
He did, see The Dark Empire Sourcebook. Or, better yet, see this.
Nephthys
And kill non-humans.
This has been retconned by the prequels and, more specifically, "Aliens in the Empire" by Abel G. Pena, which confirms that Palpatine saw everyone has pawns and had no particular personal disdain for nonhumans. That's an old Zahn-inspired holdout that has no basis in current canon.