They have the lowest prices on the market for large purchases. The fee is negligible. Try buying such quantities elsewhere without KYC, you will pay much more.
I can't comment on that. I haven't used many other exchanges to trade monero. However, it's available on Bisq. That's a decentralized exchange, meaning that you as a seller can set the price yourself. You can earn whatever premium on top of the market price you want as long as the other party agrees. You can even sell at a loss if you want.
They probably have a philosophy that holding Monero is inappropriate, considering the possible sharp drop in price upon delisting.
Monero has already been delisted by the biggest centralized exchanges and the price took a hit when that happened. CEXs where it's still traded like Kucoin, Kraken, or Bitfinex could have delisted the coin a hundred times by now, but they haven't. And even if they do, I don't think the impact would be as big as it was when bigger names did it.