If it doesn't maximise properly when autohide is enabled, then yes, that's a bug. I had another display bug to file, so I'll confirm yours as well and file them both.
As to whether the lolly interface is a bug is somewhat subjective. Microsoft violate this with their own apps (look at the menus in Office 2003) - though not as badly. Given it occurs regardless of the window style, as you've noticed, I'd say it is a deliberate decision and unlikely to be changed. Since I work on the trouble-ticket system, I can also see if any customer has reported it.
I don't know who makes the decisions as to what the trial version does and doesn't do, but I can guess. And that means I can guess as to the reasoning behind the trial version not removing anything: the trial version shows you what it's detection algorithms are like.
Wade.