I actually went through the whole escapade yesterday (!), it's actually relatively simple (well, the Disney part was, the 12 hours in the arirport/ on planes wasn't
).
As long one of your leaders sends an email off to access control, you'll be able to pick up an ID without any problems. If your status is now CT, you will be taking a photo (so keep that in mind). Otherwise you may or may not be taking a photo (depends if your leader sends an expiration date [which gets you a white ID] or not). As far as ID delivery to your resorts, I've never heard of that before and kind of doubt it. You have to show government issued photo identification anytime a new ID is made up, which wouldn't really be possible in this case.
You are supposed to show your ID upon check-in at Disney resorts, but as noted above you can try to do so without it. I would highly suggest attempting this earlier in the day- if for whatever reason it doesn't work, you'd still have time to go to access control and get your ID. If you're utilizing Disney's Magical Express (and won't have a car), the best way to get to DU is to take Disney Transport to MK -> CR, then continuing via cab ($10) or foot (not sure if they really allow this).
Finally, if you still have your expired CP white ID, bring it with you. All other TWDC IDs need to be turned in before getting your next ID, else you'll be accessed a $30 'lost ID' fee.
As far as hourly requirements for seasonal cast, it seems to vary. I tried getting a straight fast answer out of casting, but didn't get much. You'll have the best luck by talking to your own leadership.