1. 會須 is should, not "if able" (http://www.zdic.net/cd/ci/6/ZdicE4ZdicBCZdic9A80639.htm)
2. 鐘鼓饌玉 (http://www.definition-of.net/%E5%AE%9A%E4%B9%89-%E9%92%9F%E9%BC%93%E9%A6%94%E7%8E%89)
3. I must be useful SINCE Heaven endows me with talent. Li Bai does not think there's an "if" about his talent.
4. High hall, white hair sound weird.
5. Your chinese is not as good as I thought. Sigh...