Proof of Stake. You will need to buy at least 10,000 NSR. Chunks of 10k will automatically try to find blocks after 7 days if your wallet is unlocked or “unlocked for minting only.” Please note, that in this 7 days your transactions “matures.” If you spend coins from the transaction partly (creating outputs), your maturity coinage will be reset. So just leave them 
Every chunk of 10,000 NSR will give you a change to find a block.
If NuShares will become 1$ one day, a decent investment can make your living as you’re getting 40 NSR for every block found as reward. If NuShares will not reach 1$ in a foreseeable future: no, that’s unlikely
Who can say for sure?