fwiw, i got a new phone and did all this again, but this time, instead of DELETING apps i was not sure about, i made a /system/apps-removed/ directory and MOvED them into that, so that i could go back one-by-one and figure out which ones caused it...
any who, i found this out:
MLT.apk - without this, you can only make calls over wifi.
LGUniTelephonyProvider3.apk - without this, you can't make calls and you have no wifi, and you get getting that damned popup notification about com.android.phone stopping.
i think upsell.apk may have played a part in this, but i won't know for sure until i move it, which i'm about to do...