Using stats to define players

[Spicymoose]

What numbers are considered very passive, passive, aggressive, super aggressive for post flop aggression? I would guess under 1, 1-2, 2-3.5, 3.5+, but I´m really not sure.

Also, I have heard that the numbers change depending on someones VPIP, such that if someone is super loose, a 1.2 postflop agression might make them a pretty agressive player.

Lastly, after what number of hands do you begin to trust VPIP, PRF, and agression levels? After 20 I would imagine that you have a vague idea (although the read could potentially be way off). After 50 I would trust the read to a decent level of confidence.

What other stats do you use fairly often to know about your opponent? FRB? WSD?

Anyone care to share their opinions on the matter?

Thanks,
Spicymoose