Person A: 你快乐吗? - Are you happy?
Person B: 我常常是。-I often am.
Person A: 有意思。- Interesting.
Person B: 你没有不对。- You are not wrong.
Would this exchange make sense to a 中国人？ Does it sound natural and are the translations correct?
"你快乐吗?" sounds normal enough
"我常常是" sounds too 'English' . Native Chinese would reply: "我常常都很快乐"
"有意思" sounds normal enough, but it implies the answer is somewhat unexpected
The last line has the most problem:
"你没有不对" means "you didn't do anything wrong"
For "you are not wrong" in this context, native Chinese would say: " 你说得对" or "你说得没错". Both mean "you are right"
I'm afraid I fail to see why that is 'interesting'. I'd put it like this:
A: Are you happy? 你开心吗？
B: I often am. 我通常很开心。
A: (That is) Interesting. 这很有趣。
B: You're not wrong. 你没说错。
（Me: Really? Why? That's very normal.真的？为什么？ 这很正常丫！）
A: Are you Happy? 你是开心果？
B: No, I'm Sleepy? 不，我是瞌睡虫。