Make sure the box in the 2848 is checked to instruct the IRS to send copies of notices to the POA. ATX defaults to an unchecked box. I have made a 2848 template with that box checked so I do not overlook it.
One crucial question before your final decision to take this client: do you have a nice big desk with a goodly and comfy space underneath it? Big enough to hide in for a while, with your jumbo-sized bag of Skittles (or snack of choice), when it gets overwhelming? If not, refuse the engagement!
Good luck. I personally can't sit through tax classes that long without entering into a coma.
Just finished my 40th hour of CE today! Done for the year.