i am taking Chinese at school and my teacher is from china. he is hilarious! its not a making-fun-of him type of humor. you can tell its actually a joke. and its not misunderstanding either.
I'm not so sure about the "Sense of Humor" part, but I can assure you that most Chinese are respectful. Our culture teaches us to be respectful, so yes, it's an important aspect of our life. However, you're bond to find disrespectful Chinese and those with no sense of humor. It really depends on the individual. Maybe your Chinese teacher happens to be both, I assume?
You know, not a lot of Americans would take Chinese. In my school, only a few students are taking Chinese and everyone else is taking Spanish. So kudos to you. Mandarin is a VERY useful language and also the most spoken internationally. A lot of people in Asia, like Singapore, Taiwan, Cambodia, Vietnam, etc actually know Mandarin, so it'll definitely help you in the future if you chose to visit these Asian countries. Good Luck with your studies. =D
I think humor is an individual talent that can be found within all races and cultures. You are appreciating and are entertained by such a talented man.