Yes.
This is necessary, because you still secure the network, validating transactions. So it is different from mining because you don't share enormous amounts of hashpower, but by keeping the wallet on, you still contribute to the background crytpwork.
Ah ok, wish I knew this. I've been missing out on thousands of Mintcoins then by not having it open. Damn....
Bear in mind that your coins will not stake at an fixed rate for every block minted (every minute).
You put some of your coins in staking-blocks, you decide the amounts. Every block (every minute), similarly to the mining process where one miner is awarded with a block, every staking-block you put at staking will have a *probability* of generating a reward. This probability rises with the amount of coins you put to stake and with their age (how much time they stake without a reward).
But if yous take over a long time, like a year, you will get the 2,5% stake.
so with PND if I have 10,000,000 at the start of the year I'll have 10,250,000 by this time next year?