We're quits = we're finished This can refer to a debt, or even an argument. So yes, it does mean: 'We're even."

we're quits= we are finished

We're quits means You don't longer owe me a favor because you have just returned it to me. What is this in Chinese?

yes...I've never heard anyone say that though. Maybe they say it in England?

We are quits = We are no longer a couple Quit like quitting a job, but quitting a relationship. Never like we are even.