Mad Max is a single-player game. There is no multiplayer component (the "Online" leaderboards for death races are not actively monitored by Warner Bros.). You will not get banned.
This is the flagship feature. Max will not take damage from enemy fists, bullets, or environmental hazards (like fire or falling). In some versions, extreme fall damage (out-of-bounds) might still kill you, but standard combat makes you invincible. mad max trainer mrantifun