#1 and #2 have been observed in other planets in our solar system. I’m unaware of any instance of other planets “zipping off” due to wobble characteristics.
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As for #3, since the earth is suspended in the vacuum of space, it wouldn't exactly "zip off", at least not very far, IMO.
Imagine a temporary imbalance and the problems that would create. Since our planet has a semi-fluid interior and a solid inner core, things could move about, more or less, independently of one another.
Some studies indicate the core spins slower than the mantle. I can see where that's very likely, due to tidal forces.
Just some interesting conjecture. I'm not trying to rewrite any current geology texts. At lest not yet...:)
Link to earth's wobble data: http://hpiers.obspm.fr/eop-pc/images/pole.png
PM if you want to discuss further.
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