There was already an existing bug report in Bugzilla when I first ran into issue 1) years ago, and I added my comments to it.

Issue 2) I haven't. As annoying as it is when it does happen, it's not that common and although requires some extra steps, doesn't result in looking unprofessional to clients like in 1). However, there has been a few instances lately where my staff have created new subfolders within a shared imap folder and moved e-mails into them, and I've been unable to find those emails until I recall this issue. So it's probably worthwhile to start gathering details and file a report to prevent this interruption in workflow.