If I crew a vehicle with a creature that has an enchantment that does something such as "Whenever enchanted creature attacks, its controller loses 2 life" would that transfer to the vehicle it crews? Also, would enchantments such as a +1/+1 counter move to the vehicle?
No to both. Crewing a creature doesn't cause he vehicle to be related to the creatures that crew it in any way unless the creatures have an ability that triggers when they crew a vehicle. Crew means nothing more than what the ability says; that you tap creatures to make the vehicle into an artifact creature until end of turn.
From the gatherer rulings on Smuggler's Copter:
Creatures that crew a Vehicle aren’t attached to it or related in any other way. Effects that affect the Vehicle, such as by destroying it or giving it a +1/+1 counter, don’t affect the creatures that crewed it and vice versa.
Also note that "enchantments such as a +1/+1 counter" makes no sense. A counter is a completely different thing from an enchantment. If you meant an aura enchantment that gives the creature +1/+1, this is unrelated to a +1/+1 counter.