No. If there are no profits, you pay no profit share to the Copy Leader. Only actual realised profits from your Copier account are subject to the profit share charge. No profits means no profit share is payable to the Copy Leader.
Do I still pay trading fees if there are no profits?
Yes. Standard trading fees, funding fees, and any slippage still apply to your trades regardless of profitability. These are standard costs of trading on BitMEX and are separate from the profit share mechanism.
The profit share is the only fee component that depends on whether you make a profit. All other costs are incurred as trades execute.