Hi Madan,
1. User to whom request will be escalated can receive email notification on request escalation. Just configure MSMP to send notification to current approvers when escalation event will be triggered.
2. You can chenge period for sending reminders to other value - it depends on your business needs. But it sill should be executed at least daily.
3. You can configure escalation not to escalate approved line items - see SAP note: 2008881
Regards,
Rafał