Only coins that mature with a UTXO greater than 100 QTUM will be counted as staking. Coins will mature after 501 approvals in the blockchain. Note: Splitting a coin will reset the maturity level.
Rewards are selected at the address where the block is minted, and are distributed when the block is minted. Rewards are automatically distributed from the blockchain, so there is no action to "accept" a reward.
Send and receive tokens freely while staking. Since there are no restrictions, staking can't be unlocked (there is no need to unlock). Since there is no unlocking, there is no lock period, etc.