Here are my final observations and I want to be sure this captures everything and would appreciate your thoughts:

1. If I assign jobs on the timesheet, the payroll expenses for the employee will show up on the Job Profitability reports when I run payroll based on the hours worked on that job/total hours recorded for the employee over the pay period.   This happens even when the hours are not billable.  This includes any payroll item I have checked "Track Expenses by Job", in addition to Salary/Wage items.
2. The Service Item in the timesheet only functionally helps when you are creating an invoice for the billable time by populating the Service item at Invoice generation.  There is no automatic mapping of any payroll expense to the underlining expense account of the Service item, that is a function of the Cost amount that is input when setting up the Service Item.
3. Any chart of account mapping of payroll expenses must be done when setting up the payroll item.  If I want the payroll expense of an employee working on a job to be mapped to a Job Labor COGS account, I must set up a payroll item to do so, select it in the timesheet, and run payroll.

Is that all correct and am I missing any other setup/functionality item when working with timesheets?

Thanks,

Tim