Process after you mail the form?

So, I was reading the sticky where everyone is saying how far they are and on what date they received everything, and I'm getting very confused. I'm wondering if somebody can confirm if I understand the process correctly and/or if i'm missing something.

So the way I understood it the process goes like:

• You mail it
• They receive it
• They send text/email confirming that they have everything needed to start review. (And around this time they process the payment)
• We receive letter saying same thing as text/email. (is this the 797?)
• They review the application.
• We receive another letter saying if we are approved for deferred action or if they need something else. (is this another 797? Or something else?)
• Once approved, we get the Biometric scheduled/done.
• They start/process/finish EAD after the main application is approved(After biometric or is this done same time?).
• Finally, we get the authorization. (Another letter I guess?)

I'm confused about the email/text, do we receive information all along by this method, or do we only get the initial message that way and everything else by mail?

I'm also very confused about the sticky where people keep saying that they have been accepted/approved. I'm not sure if that means people are at the step where they have said that there is enough information to start the process or if they have already had their application reviewed/processed. As far as we know, has anybody actually had their application approved so that they are only waiting for biometrics and the EAD?

The email/txts notifications are just courtesy updates on your case. ALL official update regarding your case will be send via snail mail.

"Under existing regulations, an individual whose case has been deferred is eligible to receive employment authorization for the period of deferred action, provided he or she can demonstrate “an economic necessity for employment."

This condition is trolling the shit out of me. Some might get their i-821d approved but not their i-765 and end up not getting a work permit. In a way it makes sense since those who submitted form g-1145 have received two notifications. I wonder what document one will get if one's i-821d is approved but not i-765.