if you want to get technical, the first one is correct. "you've" is a contraction of "you have" which would make the perfect past tense "you have never spoken" indicating a completed action. realistically, both are OK to use, especially in America, but the first one sounds more natural.

Both are correct. Just learn when to use them.

"You never spoke to me before" is correct or you can say "You have never spoken to me before" which sounds alot better.