Hi,
I'm in the same situation as Alex. I've tested the setup you suggested. It mostly works, except for one thing.
When I delete a message in AquaMail, it shows up struck-out in Thunderbird - so far so good. Suppose I decide it was deleted in error, and undelete it. The problem is, AquaMail a) never shows the message again, and what's worse, it b) keeps re-deleting the message every time it refreshes the folder. I could perhaps live with a), but b) defeats the whole point.
AquaMail should ideally sync Deleted flag from IMAP server. Every other email client I've ever used does this.
Thanks,
Igor