Congratulation! Any of those schools will be a great place for you, no doubt. But if I were you, I would choose UW Seattle. It is one of the most highly esteemed programs in the world. You will have no problem finding jobs in both industry and academia from UW.
I guess UNC will not provide (TA) funding for most of the international students. And without funding from UNC, it is better to choose fully-funded UW Madison.
To @BStat: Oh really? Exactly same choices? What a coincidence! I am happy to find someone who is in the same boat.
And thank you @Bayesian1701 and @bayessays for your advice. Unfortunately, the fellowship is for the first year only. It is really hard to decide...
Got rejection from UC Berkeley biostat... Well, I think I should decide between OSU(stat, fellowship) and NCSU(stat, TA). If anyone has thoughts on these schools or advice for me, I'd appreciate hearing it. I am still undecided on the industry vs. academia career choice, and I have interest in Bayesian methods & machine learning.