Questions about Arbitrum and gas…

I have several questions regarding Arbitrum and gas. I understand that gas fees on Arb1 are paid in ETH that has been deposited to Arb1 (let's call this arbETH). My questions are:

1) Who gets paid the arbETH on Arb1? Is that the transaction sequencer?

2) Who is allowed to operate transaction sequencers on Arb1?

3) Does the sequencer operator then withdraw arbETH from Arb1 from the deposit contract on mainnet?