Dear Tushar,
For your first requirement, its already supported with Afaria. Go to Server Configuration, and under security uncheck the Automatically Approve device checkbox. This will take the device to the unapproved state and in the alerts you can see the alert is been created that pending approval for devices. Under Alerts you can go to the Defined Contact Tab and configure the alert Response.
I am not sure for the Second requirement.
Hope this helps,
Thanks,
Rakshit Doshi