Looking for some quick advice about baggage

Hi r/travel,

I don't frequent here, but figured this would be the best place to ask this question. I'm returning home from Taiwan back to the US tomorrow, and am returning home with an Erhu (Chinese violin). When I traveled here with my girlfriend, Cathay Pacific made a big fuss about a violin traveling in the cabin, and I don't want to have that problem again. Is there anybody here who might know any good ways to make sure I can carry my Erhu on to the plane with me? It's pretty fragile, and would rather not have it down in the hold. It's also been my first time traveling abroad, and I've gotten a little confused looking at the customs website. I'm bringing beer home for a friend, and since it is over a liter (1.8L), I have to declare it and pay duty on it, correct? I've got it all ready in my checked baggage, but just wanted to clarify a few things.

Thanks a bunch in advance.