Email Alerts on New and Assigned Incidents

Stefanie Cortese 

For Question 1, you could:

1. Assign a Playbook that sends an email, to all your Alerts/Rules? https://docs.microsoft.com/en-us/azure/sentinel/tutorial-respond-threats-playbook.   You just need these two steps "When a trigger.." and "Send approval email" , from the diagram in step 9.  This is my preferred option.

You could instead create a new Alert in Sentinel that runs (every 5mins, which is the shortest interval), using logic like this below (just a sample, which you need to check), then attach the "send email" playbook to that Alert only. 
A variation would be to do this in all in a Playbook, with the trigger being a scheduled event (search for "Recurrence"). 
However please note, there is a cost for executing a playbook (if you wanted it once per second, that will add up!).

sample logic, you may need different filtering or data displayed.

SecurityAlert
//| where TimeGenerated > ago(1h)
| where ProductName == "Azure Sentinel"  
| where AlertSeverity !="Informational"
| project ProductName , AlertSeverity , IsIncident , AlertName , SystemAlertId