Emptry review * sign, Loading spinner when post a review

Hi, I have got a few questions.

1. When I set “Allow empty comment”, I can submit a review without writing a comment. But the comment label still got * sign. Is this a bug?

2. When I click the review submit button, there’s about 3-5 seconds delay. But the screen is very still and it doesn’t feel like the submit button was clicked. So there are times when customer click the submit button once more then they get redirected to a WordPress error page which isn’t user friendly. Is there a way to show something like a “loading spinner” to indicate that the review is being submitted?