"Therefore, their best option would be a negotiated "velvet revolution" splitting the country into East and West."
Yushchenko is almost certainly a Moscow puppet put there to steer the opposition into a series of compromises designed to trap them in a coalition government favorable to Moscow. If things get out of hand, Russian special forces in combination with pro-Putin Ukranian forces will move in and crush any genuine opposition IMO.
I don't necessarily disagree with you--primarily because I don't yet have enough information on the subject. But may I ask what makes you say this? What evidence (if any) is there that Yuschenko is a Moscow plant?