Yes, you will start earning points if you have stacked or staked your supported tokens on LISA!
No, you will no longer earn any LISA points once you have exited your current staking/stacking positions; this applies to both LiALEX and LiSTX.
Yes, the moment you start holding LISA tokens, you will begin earning LISA points. Important to note that, your earning comes the next day, not instantly.