1) Did you know the difference between a prophet and a seer?
I didn't until tonight. A seer uses his own spiritual power to peer into the future, while a prophet is more of a conduit for God (or a god). That is why prophets in the Old Testament gradually came to be seen as more respectable than seers (such as Joseph): they weren't "putting nature to the rack" (F. Bacon on experimental science) to get answers; they waited for God. Of course, necromancers were even worse: they were put to death. Their power was seen as genuine, but outright wicked.
2) The "guild prophets" wore odd haircuts and clothing, did strange, symbolic actions, went into trances, had visions, whirled about dancing ecstatically, and were regarded as very weird by the establishment: early Deadheads, clearly.