Answers

1. The defaultValue property on an input element can be used to set its initial value.
2. The problem is that the change that's been made to the firstName state needs to be managed:

   <input
     id="firstName"
     value={firstName}
     onChange={e => setFirstName(e.currentTarget.value)}
   />

3. When we tie a label to input using the htmlFor attribute, it makes it accessible to tools such as screen readers. Also, when a user clicks on the label, the focus will automatically be set on the input.
4. The errors object in React Hook Form allows us to access validation errors.
5. We can use the isSubmitting flag within formState to determine whether a form is being submitted.
6. The isSubmitted flag with formState indicates whether a form has been submitted, irrespective of whether the submission was successful.