I actually ended up unrooting precisely due to this... I'm researching and trying to figure out a way to root w/o installing things that consider the nook as a phone... A custom rom is being produced on this thread.... Hopefully it will be a lot more close to a reader than a phone: http://forum.xda-developers.com/show....php?t=1208024
IMO, both "cell standby" and "phone idle" and just about all actions that nook does when it is in sleep mode. Removing these apk's however helps just a bit because there are none useless phone apps running in background, but there still will be "cell standby" thing in battery stats.
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