The rules for entering time in QuickBooks are such that you are unlikely to every use all the fields available at once. For instance, if you are entering employee time that does not need to be connected to a job or customer, then you likely should hard code the Billable field to be "False".
Time Entry Fields
Service Item ‡
Payroll Item ‡
See this article for more information on field types.
Available in Sync & Save PLUS QuickBooks.