[A] You don't need to root to install ClockworkMod
It may be obvious to some, and this thread will probably sink into obscurity anyway, but I could have saved myself some trouble if I'd known this off the bat. A lot of threads for setting up alternative ROMs say you have to root to install CWM: false.
Basically, if you set up a bootable SD that includes ROM Manager, such as in verygreen's thread
, then you can boot to CM7, and in the ROM Manager app, "Flash ClockworkMod Recovery." This will install CWM in place of "factory mode" on your NC's internal storage, but won't touch the stock OS install. Your NC will no longer restore to factory settings after 8 failed boots, but that can be a pro as well as a con, as your data won't get wiped if the NC gets confused, for instance during an upgrade.
In most cases, you're better off running ClockworkMod from an SD and leaving stock recovery intact.