I prefer the writers to ignore us. They've done smashing work without amateur mob interference. I agree 90% with the OP.
As for political messages, they've been there from the beginning, but their subtlety and balance have lead me to believe they know what they're doing on this front, and that they don't need any help from us. If you're demanding messages, maybe you should examine the show a little closer. They're already there.
Communism is just a red herring. There's so much more in that episode for those who are willing to look beyond the culturally obvious.
Finally, if they include LGBT characters, it's going to be very hard. It should be subtle, thoughtful, and not a stereotype pretending to be "inclusive". That kind of stuff, if it can be attempted at all, should be left to the professionals to handle.
Oh and after finally, the reason people want Celestia to bite it is because this is a common, almost cliché, trope of fantasy stories. The mentor always dies. Examples: Obiwan Kenobi, Gandalf, Dumbledore. When fans demand that, they're showing their standard fantasy story expectation. The challenge to the writer will be to both deny and satisfy that at the same time and in a new way.