Yes. Delegation never transfers ownership of your ADA. Your coins stay in your wallet under your keys. You can spend, transfer, or redelegate at any time.
Rewards are distributed automatically at the end of each epoch (every 5 days), starting approximately 15–20 days after your first delegation.
Anytime. You can redelegate to another pool or deregister your stake key entirely. Your rewards accrue until the moment you move.
Pool fees are shown above. You pay one small network fee (~0.17 ADA) to register delegation. That's it.