1, if it is regular, it is estimated that your pot has not been carefully cleaned. I suggest you go home and help carefully brush the scope of the pot with steel balls and detergent until there is no dark brown appearance after hard brushing. Brush carefully after cooking every day!
2. Don't eat the burnt part if it is only occasionally burnt once or twice because of the long cooking time. Because those burnt parts have almost no nutrition, and more are just carcinogenic.
3. As for whether eating it will cause cancer, you can imagine drinking pesticides. Drinking pesticides also requires a certain amount to kill people. The same is true for eating burnt substances to cause cancer. However, if you eat burnt food frequently all the year round, it is absolutely easy to greatly increase the risk of cancer.