Hi,
1. I don't see what you mean. On your screenshot, I can see that the coinbase payment method is selected and that the cart shows the coinbase payment method fee. Which looks normal to me.
2. Supposing that you configured a percentage fee in your payment method, and not a flat fee, you can do that by editing the file show_block_payment via the menu Display>Views and changing the line:
echo $this->checkoutHelper->getDisplayPrice($payment, 'payment', $this->options);
to:
echo round($payment->payment_params->payment_percentage).'%';