Approver's name isn't needed since the email is sent to them. Plus this is a multi-valued reference attribute and you can't get those to resolve properly in the Email template. Finally the approval object points to the request and not the other way around.
As for when the request was submitted you can do [//Request/CreatedTime]. Unfortunately the timeout is set on the on approval object (ApprovalDuration). The best you could do here is say "You have three days to approve this request before it is escalated."
Then use that template for approval workflow activities that have been set to three days.
David Lundell, Get your copy of FIM Best Practices Volume 1 http://blog.ilmbestpractices.com/2010/08/book-is-here-fim-best-practices-volume.html