Hi there Gilthequeen,
If the flash and rear camera aren't working on your iPhone, removing the SIM card won't affect or help with the issue. Also, removing the SIM card could potentially create new issues with your cellular network connection.
If the flash or camera isn't working on your iPhone, try these steps: If the camera or flash on your iPhone, iPad, or iPod touch isn't working
If the issue persists afterwards, the next best step is to have your iPhone inspected. This link will help you get started: iPhone Repair and Service
Take care.