Much as it pains me to dismiss a good analysis, retaking the throne always seemed a bit bizarre. She HAD the throne; she could've removed Rahvins lackeys and rallied support as the lawful queen at least as easily as a mysterious stranger banished her support and built his own (if not for Compulsion, of course). It seemed to me that the main reason she fled Andor wasn't so much his tight hold on the reins of power as his tight hold on HER, the dim memories of all the times she'd thought of resisting, rebelling or fleeing only to have to fall meekly and silently in line at a gesture from him. It's not like obtaining a foreign army and invading Andor with him at the head of her OLD army would make that any less likely than if she'd simply tried to set the Guards on him.

When she fled Caemlyn Morgase was finished as a ruler, whether she knew it or not, and her best bet would've been to seek a sanctuary as an EXILE, not a pretender. The best candidates for that were probably the Borderlands or Tear, neither of which have an antagonistic history with Andor, and both of which would've seen the value of a link to Elayne by marrying one of their senior nobles off to her mother. Tear would've leapt at the opportunity to triangulate against Cairhien, and the Borderlanders would have treated her with at least nominal respect as a woman as well as a noble. Best bet, IMHO, would have been to go a-courtin' the widower king of Arafel, though by all accounts of him it would've been a fools errand. Any attempt to regain the throne was almost certain to end in disaster sooner or later, if only when Rahvin was brought to her in chains and commanded her to release him and execute her own army.