PT What if Grievous killed Obi-Wan?

How would that have changed things? Obviously aside from Obi-Wan not being on Mustafar, no Vader burning, etc. What would Palpatine have done in this situation?

 

In the RoTS novel, the narration implies that Palpatine thought of Obi-Wan vs Grievous as a win-win situation for him:

When constructing an effective Jedi trap—as opposed to the sort that results in nothing more than an embarrassingly brief entry in the Temple archives—there are several design features that one should include for best results.
The first is an irresistible bait. The commanding general of an outlaw nation, personally responsible for billions of deaths across the galaxy, is ideal.
The second is a remote, nearly inaccessible location, one that is easily taken and easily fortified, with a sharply restricted field of action. It should also, ideally, belong to someone else, preferably an enemy; the locations used for Jedi traps never survive the operation unscathed, and many don't survive it at all. An excellent choice would be an impoverished desert planet in the Outer Rim, with unwarlike natives, whose few cities are built in a cluster of sinkholes on a vast arid plateau. A city in a sinkhole is virtually a giant kill-jar; once a Jedi flies in, all one need do is seal the lid.
Third, since it is always a good idea to remain well out of reach when plotting against a Jedi's life—on the far side of the galaxy is considered best—one should have a reliable proxy to do the actual murder. The exemplar of a reliable proxy would be, for example, the most prolific living Jedi killer, backed up by a squad of advanced combat droids designed, built, and armed specifically to fight Jedi. Making one's proxy double as the bait is an impressively elegant stroke, if it can be managed, since it ensures that the Jedi victim will voluntarily place himself in contact with the Jedi killer—and will continue to do so even after he realizes the extent of the trap, out of a combination of devotion to duty and a not-entirely-unjustified arrogance.
The fourth element of an effective Jedi trap is a massively overwhelming force of combat troops who are willing to burn the whole planet, including themselves if necessary, to ensure that the Jedi in question does not escape.
A textbook example of the ideal Jedi trap is the one that waited on Utapau for Obi-Wan Kenobi.


As has been said, the textbook example of a Jedi trap is the one that was set on Utapau, for Obi-Wan Kenobi. It worked perfectly.
The final element essential to the creation of a truly effective Jedi trap is a certain coldness of mind—a detachment, if you will, from any desire for a particular outcome.
The best way to arrange matters is to create a win-win situation.
For example, one might use as one's proxy a creature that not only is expendable, but would eventually have to be killed anyway. Thus, if one's proxy fails and is destroyed, it's no loss—in fact, the targeted Jedi has actually done one a favor, by taking care of a bit of dirty work one would otherwise have to do oneself.
And the final stroke of perfection is to organize the Jedi trap so that by walking into it at all, the Jedi has already lost.
That is to say, a Jedi trap works best when one's true goal is merely to make sure that the Jedi in question spends some hours or days off somewhere on the far side of the galaxy. So that he won't be around to interfere with one's real plans.
So that by the time he can return, it will be already too late.

 

Too late indeed. Obi-Wan left his friend behind on safe secure Coruscant and went off to end the war and bring peace to the Republic. When he returned to the capital, the Jedi Order had been massacred by his former student who had turned to the Dark Side.

The Emperor had already won. Now all Obi-Wan could do was attempt to correct a fatal error.

 

What would Palpatine have done? Not much differently. The Jedi Purge was already in effect by the time he got back. And Vader's path to the dark side still probably would have been the same, just without getting his limbs cut off and not having to wear the suit.

As for Luke, I imagine Bail Organa would have found someone else to take care of him, but then Luke would have never gone to the Death Star, saved Leia, become a Jedi, etc. So the absence of Luke in the Rebel Alliance would be the main way Obi-Wan's death would have affected the galaxy, in my opinion.

 

Does Padme even go to Mustafar if Obi-Wan doesn't show up and tell her about Anakin killing younglings? Does Padme still get choked on Mustafar if Obi-Wan doesn't show up at all? Does Padme still "die"? Does she die away from Vader? Does she give birth away from Vader?

 

Things would've been a lot worse, probably. Anakin likely wouldn't have killed Padme, meaning there's a good chance that Luke and Leia would have been raised under the Emperor's influence, and Obi-Wan would obviously not be there to help them.

That being said, if Vader never got toasty, he may have surpassed Palpatine at some point and killed him anyways. Since he's a butcher, not a political leader, the Empire would pretty much be in the same position as it was post-ROTJ (I think it's safe to assume some Imperial Remnant/fractured Empire must exist, even disregarding the LEU).

What would've happened to Grievous? Same as the rest of the Separatists. To win public support, it wouldn't make sense for Sidious to have a former Separatist spearheading his new Empire. So, Grievous gets disposed of, probably by Anakin.

 

One major question that I am wondering though is what would happen to Grievous? I doubt he would join the Empire. Plus, Palpatine needed the Jedi to come and attack him to give an air of legitimacy to Order 66. Actually, now that I think about it, they'd still go after him just for revealing himself to Anakin, but either way Grievous remaining in the picture might change things. Or would it simply be that he rejoins the Seperatist Council at Mustafar and is killed by Vader?