To protect your investment in the YF Link ecosystem by voting and because you want the project to be successful. You use your voting power to make sure that things that bring positive value to the project happen.
Anything worthwhile takes time. To this end we have a proposal reward for 1 or 2 YFL depending on the majority to compensate for time spent on writing and putting up a proposal.
Your yYFL is locked as yYFL in the Voting Contract that was set up by the voter. This yYFL is only accessible with the wallet used to set up the voting contract. For a single-wallet setup, only that wallet can withdraw $YFL out of the system.
No, voters who are active in governance can leave their $YFL in the voting contract to save on gas fees. However, this is done at own risk.