How does my coin switch to stake mode ?
By having it in your wallet, your wallet open and not encrypted.

My coins go in stake mode automaticaly after 6 hours.
It is 6% interest rate.
Everyday with 1000 staked cloakcoin I should expect +2.9coins ? 1000 * 1.06 / 365 = 2.9 coins
If my wallet goes offline for a week wtih 1000 staked coins, when it comes back online, does it have + 7 days interest ( approx +20 coins) ?