All "o" are not exactly like in the word "bone". That one is ô in French. Long and round.
Our "o" (au, eau, and o without accent) are a bit shorter. As a rule, we don't sing or drag letters like we do in English. To give you an idea, the name Paul, in English sounds like Po-o-o-l-l (to me) whereas in French it's Pol. (about 3 times shorter!)
"os" sounds like osss - short o, long s.
"oz" sound like ozzzz - short o, long z.
No "u" sound at all, though I have no idea what the chinese "u" is...