Part A: Can someone else other than the Timesheet Manager approve Timesheets?
This can be done however would require some configuration of permissions. As we all know, it is very easy to set up a single person as the Timesheet approver for any resource by setting the resource’s Timesheet approver in the Resource Center page. However, it is more difficult to set up a "chain" of Timesheet approvers.
This would also require that the Team Members would need to select the Next Timesheet Approver (and would require a configuration change).
Part B: How can an in-process Timesheet be approved if the Timesheet Approver is out of the office and not able to access the system?
This is a manual process which would require:
1) The submitter (Team Member) must recall the timesheet.
2) The administrator (or user with permission) must change the timesheet manager for the submitter to the new approver.
3) The submitter must resubmit. Only then is the timesheet re-routed to the new approver.
4) The new approver can approve the timesheet.