1. CUE and IPCC are included topics. So yes you will need to be proficient with scripting.
2. This may help.
http://www.cisco.com/univercd/cc/td/doc/cisintwk/intsolns/voipsol/dp3_isd.htm#xtocid8
3. Yes you may have to change phone load from SCCP to H323 and back. When I practiced for my lab i had two ATAs all the time as its a pain to convert it back to SCCP once its converted to H323. You have to be on the phone and punch a few key sequences from the phone to specify ip address of tftp server where you can download the SCCP image from.
HTH
Sankar
PS: please remember to rate posts!
Sankar Nair
UC Solutions Architect
Pacific Northwest | CDW
CCIE Collaboration #17135 Emeritus