Question: Trying to determine best practice in queue management. New setup - want to see if it's best for users to always take ownership of a case and then close it at a user level. Or if it's OK for cases to be closed at the queue level, with the queue as owner.

Answer: 
In my opinion, it's always best for an actual owner to be assigned, simply for metrics, but also for tracking if followups on "who closed this" are necessary.
If nobody's "owned" the case, then it probably shouldn't be closed. The sole exception to this rule of thumb would be when an automated system resolves the issue (e.g. a password reset), or the case is a duplicate, etc. Otherwise, the person that resolves the case should be the owner of the case. This could help in case the customer needs to re-open the case (in which case the owner needs to take action), etc.