Just read ocCULT by June Summers; the cult in this story began as a pretty normal 'pentecostal' church but quickly morphed into craziness. The paralels to UPC are subtle but obvious. Is UPC a cult? Here are some of the definitions of a cult:
Beliefs, values, or practices contrast with the normal culture or tradition YES

The group is led to believe that only they have 'the truth' YES

Members usually believe that their group is singled out for persecution PRETTY MUCH

Leaders control members by getting them to believe they will face death, God's wrath, etc. if they walk outside the group YES

Decisions are governed by the rules or ideologies of the structure/leader YES

Complete obedience is expected within the group PRETTY MUCH

So, is the UPC a CULT? Oh, yeah, . . . . ..