Yes, you certainly can still earn PoS after encryption. But you do need to unlock the wallet to stake. You will not be staking by 'default' after encryption as soon as the software loads. Not until you unlock. You can unlock for staking only and still have protection of your OS being compromised. The password would be needed again to make any send transaction. Take note you do need to unlock for staking and spending for staking for charity to work, but the wallet now alerts you to that condition if you try.

No, you do not need to be running 24/7. At minimum, please stake for 12 hours every 30 days to be certain the 7% annual holds true. More often is recommended and would be needed for lower balances (sub 100 EGC) because 12 hours might not be enough. Anytime you are staking, you are helping the network to achieve more consistent block times. That is appreciated.

You're very welcome and thanks for staking your EverGreenCoin!!