Yes, you lose a permanent or a card leaves your graveyard because things get exiled, but it doesn't count as a sacrifice
In essence, the Kokiri share many of the qualities that elves are known for in the Magic: The Gathering
[1] If this card is Normal or Special Summoned: You can Special Summon 1 Level 4 or lower Beast monster from your Deck in face-down Defense Position, then if this card is in Attack Position, change it to Defense Position
When this card attacks, the best your opponent can do is to block with a 0/4 or have non-damage-based removal like destroy or exile
Anyhow, if you dont want to use By Force or Vandalblast, theres cool alternatives with: Fury Charm also lets you pump your creature, Molten Frame lets you draw a card instead and Gleeful Demolition is really cool for Goblin decks
Both of these mechanics are a mystery because they are so different from what has come before, and looking back over Magics history, the introduction of such new mechanics ratchets up the potential for power level mistakes