Anyhow, the wedding is just a one day affair. Put it bluntly, she is making it as if both of you are the props while she is the director. Since she is super on about the entire wedding preparations, let her be. To her, her 'face' is more important. If anything goes wrong, its not your fault.
BTW, talking about that speech she requested, you can inform her that your language skills has limitations, so may not be able to live up to her standard. Why not get her to engage some pro to write the speech for you and you just read it from there. This does not look nice to you, but since she wants the 'show' to move on, so be it.
After that wedding, you and your hubby can enjoy some peacefulness without her interruptions.
Hope you won't be offended by my words. I just find that at this point, the wedding day is not important anymore. More to that fact that u must tolerate her willfulness and craps in future.
U know, at least u have a memorable ROM, that's more than enough.