I have 4 questions!

1. Benny what is your opinion on this as far as culture goes. When greeting a stranger one should only use. 你好。Right? I heard that 你好吗？ is only suppose to be used with people you know well and that you truly care about how they are? naturally i would use 你好吗？ if i were greeting you :) if this is the case.

2. when should we use 您？ or when do we use nín? would I use it if I went to a store would i use. 您好。 您有咖啡吗？ since to my understand it is used for respect.

3. I know there are two ways of saying certain words depending where you from Northern China or Southern, but academically what is correct? the words i am curious are like 哪儿 and 一点儿 or better to use 哪里 and 一点？

4. You’re lessons what is the accent? 上海话 or 北京话？