Interesting take on The Wizard of Oz and Oz the Great & Powerful

I read this theory on reddit.com and it was posted by TurtlingTerran. Though I love and agree with the theory and the comment I posted from the thread, they were not thought up by me.
------------------------------------------------- Theory:

!!WARNING!! Spoilers for Oz below
For the sake of clarity and brevity, Mila Kunis, will be referred to as WWG, or wicked witch green. Not Mila Kunis will be WWY, or wicked witch yellow.
First: Oz establishes the existence of “conduits” for witches. Glinda’s conduit was her wand. Not Mila Kunis’s conduit was her green-jeweled necklace. It didn’t appear that Mila Kunis had one until the broom, but we’ll discuss that later. It was mentioned both in Oz and the Wizard of Oz that the only way to destroy a witch is to destroy her conduit: Oz was supposed to break Glinda’s wand, Dorothy was supposed to retrieve the broom of WWG (who made the broom her conduit in defiance of WOZ). But what is a conduit? I believe that in exchange for a part of themselves, their souls or essences or whatever, imputed into an inanimate object, the witches gave themselves both greater power and possible immortality.
Second: There appear to be two types of magic, similar to the force. So far, we’ve only ever seen destructive magic utilized by evil or evil leaning witches, whereas Glinda’s magic seemed to be more passive, shields and fog and bubbles. This is why WWG being neutral in the beginning was such a big deal. She was essentially powerless as long as she did her best to remain neutral. She fled from ONE winged monkey, cowered from the lion, etc. She did show magic when she was displaying her temper, which was fierce, which brought her closer to the evil side of magic. But why did she only display magic when she was emotional? Her already evil sister commented on how great her sister’s temper was, and when she was very emotional she, like a tiny green ball of rage, wasn’t really able to use her power in a controlled fashion.
Third: The conduits allowed the witches to control their magic, and if using the proper conduit, made them stronger. When the bubble shield was being attacked, Glinda remarked that WWY wasn’t strong enough to breach the wall on her own. I believe that this was because Glinda knew a very important fact. That there are TWO types of magic and thus TWO possible types of conduit, and that while Glinda was good and using her good conduit, WWY was evil and using her good conduit, which made her weaker as her magic and her conduit weren’t aligned. I believe that this is how WWY was able to survive her conduit being destroyed. When she had created her green-jeweled conduit, she had done it with good magic and imputed her good self into it. However, by the time the conduit was destroyed, she was no longer good, and thus it didn’t truly contain her anymore. But without a conduit, and without her sister’s great rage, she wasn’t capable of performing magic to fight Glinda.
Fourth: So what was Mila Kunis’s original conduit? Her heart, which was destroyed by her sister’s spell. Somehow, in her naïve, overly powered way, she had managed to make a piece of herself her conduit, and attempting to force her temper-powered magic through her good conduit was what was preventing her from going over to the evil side. Which is why both sisters experienced a transformation when their good conduits were destroyed, and not total destruction. A magical backlash of evil will do that, apparently. And as stated above, it clearly appeared as if WWG was making the broom her conduit, when she grabbed it and warped it to be more fitting of her.
Fifth: So why does this matter? Think about the plot of Wizard of Oz. Dorothy dropped a house on and “killed” WWY, leaving her MAGICAL RED SHOES! We’ve already seen that WWY likes making shiny things her conduit, so it is not a leap at all to believe that she made the MAGIC RUBY SLIPPERS her true, evil conduit. But as we already know from OZ and WOZ, the only way to truly destroy a witch is to destroy her conduit. So, the plot of the Wizard of Oz is actually about WWG doing everything in her power to get back her sister’s conduit so that she can magically bring back the only person she actually cares about. And she was willing to do anything to get that person back. Meanwhile, Glinda and WOZ are manipulating a simple farm girl into doing what they won’t do themselves in order to end a decades long turf war for control of the land of Oz...

Adding to it was a comment by Gamezeta:

My theory is that the red ring was the wwg "conduit." After the wwy conduit was destroyed by Glinda the wwy lost her power to use magic. After the wwq decided to put some of her red ring magic into slippers for her sister. (Perhaps she put the rest of her power into her broom. This explains why the wwg is so desperate to get her slippers back in Wizard of Oz. Wwg is trying to reclaim all of her power.