How much caffeine does oolong tea have?

So little, only around 50mG per Cup of oolong Tea, You can read more about it at the related link below.

yes

I am pretty sure it depends on the tea. I'm not entirely sure, but it depends on the types like green or black. Also, the amount that you use. generally one bag of green tea has about 30mg caffeine

1,359.33 milligrams per 100g

not alot