A: No. Copyright law does not care about profit. Distributing a modified version of Supercell’s intellectual property without a license is still infringement.
Community projects like Clash of SL (CSS) or Atrasis develop open-source or proprietary emulators that mimic official server behavior. These "server files" typically include: Server/Client Design for Clash of Clans Like Game clash of clans server files
Can you use a private server to test attacks and then use that knowledge on official servers? Technically, yes. But if you ever log into the official Supercell server from a device that has a modified client installed, Supercell’s anti-cheat ( Trust & Safety ) will flag your device ID and hardware. Result: Permanent ban. clash of clans server files