If the targeted permanent is an illegal target by the time Into the Roil resolves, the entire spell doesn't resolve. You don't draw a card.

If the target nonland permanent is an illegal target by the time Into the Roil tries to resolve, the spell doesn't resolve. You don't draw a card if it was kicked.

The kicker ability doesn't let you pay a kicker cost more than once.

If you put a permanent with a kicker ability onto the battlefield without casting it, you can't kick it.

If a spell's kicker cost was paid, the spell is "kicked."

If a card or token enters as a copy of a permanent, the new permanent isn't kicked, even if the original was.

To determine a spell's total cost, start with the mana cost (or an alternative cost if another card's effect allows you to pay one instead), add any cost increases (such as kicker), then apply any cost reductions. The spell's mana value remains unchanged, no matter what the total cost to cast it was.

If you copy a kicked spell on the stack, the copy is also kicked. If the copied spell is a permanent spell, the token the copy of that spell becomes when it enters is also kicked.