It takes around 3-4 epochs for your first rewards to show up. It is 15-20 days. This is the same for ALL pools.
Cardano protocol is taking a snapshot of the delegation status for all wallets between each epoch. The delegation choice will become active 2 epochs later, and the rewards will be paid out after 1 additional epoch
After the initial 3-4 epochs, your rewards will be deposited after each epoch - which is 5 days.
Yes! You can easily and freely change your delegation at any time to another pool. You will still receive rewards every epoch.
Your rewards are automatically staked. There is no need to withdraw rewards manually after each epoch.
No, rewards amount fluctuate from epoch to epoch. This is the same for ALL pools.
No, payment schedule is exactly the same for all pools on Cardano. Payment of rewards is handled completely by the protocol. Pool operators simply make the blocks, and the protocol distributes the rewards based on stakes.