1) Do you speak ( *by speak, we mean ability to comprehend and
articulate any dialect?) If no, what language do you speak mainly and
SKIP QUESTION 2)

yes

2) If yes, to whom?How do you rate your proficiency level?
(comprehension only, or plus articulation)

friends and elderly. Fairly articulate.

3) Do you find that Mandarin is replacing the role of dialects in places
eg. home/market/hawker centre? If yes, has Mandarin "diluted" your
dialect? (eg. do you replace the words you can't say in dialect with
Mandarin instead?) 

no

4) What is your opinion of people who speak dialects?

 just another dialect. Mandarin is a dialect too, albeit one glorified by the People's Republic of China. I feel nothing towards them. Not better nor worse, because it is just another dialect/language. I do not believe in the superiority of any language or dialect, if you are trying to lead me that way. I am Hokkien, and I speak quite a few dialects, not very fluently though. And when you finally grasp the diversity of dialects... you will know what I mean.

5) Given a chance, would you join classes provided for the learning of
your dialect?

I prefer informal learning

6) If you have children of your own in the future, would you want them
to learn your own (or any) dialect? Why and why not?

up to them