Which of the following statements are correct?

This is true. It is in the interest of the consumers that their switching costs are as low as possible. This way, in case of inconveniences like price increases, the customers can easily switch to another supplier.

This is true. If customers know their switching costs (e.g. termination penalty) they can negotiate with the potential new supplier and get a goodie or price reduction such that switching to this new supplier gets advantageous for the customers.

This is correct. If customers have bought many supplier-specific complementary goods, then their switching costs are quite high. This is due to the fact that they would have to buy new complementary goods when they changed to another supplier.