Hey Kelly,
I want to make sure I understand what you are saying... When a Lead is synced to SFDC and there is no Lead Owner, the Lead is assigned to a Queue. And seeing how a Queue is general, any associated task to follow up is assigned to no one, or not created, and the Lead sits in your system in anonyminity. That right?
If so, I would have a an alert email sent to yourself and an appropriate Sales Manager when a Lead is assigned to the Queue. This way each Lead can be addressed in real time and assigned to a different rep manually, or maybe dropped into an Engagement Nurture.
Just a thought!