I would personally consider all of the questions in that survey flawed in one way or another. Let's analyze:
1. How old are you?
The answer is a text-box, but it should use age-ranges to provide a certain anonymity set. I'm certain that a fair amount of people do not want to reveal their age.
2. Do you have bitcoins or any other altcoins ?
yes, no
Why would people who don't have any Bitcoins or altcoins use Bitcointalk in the first place?
3. How many Bitcoins or any other altcoins do you have?
Same problem as with the first question. e.g. ranges like: 'less than 1', 'more than 1', 'more than 10' et al.
4. Do you think Bitcoin will replace USD in the future ?
yes, no
why
This question is just pure (and random) speculation.
5. Do you think developers will be able to solve all Bitcoin bugs to be safe?
As with every software, bugs exist and bugs are fixable.
6. How much do you earn from Mining coins?
Ambiguous question? You don't even ask whether someone is mining in the first place. Most of the people that will likely answer this survey are not miners.
7. Why do you think only few websites accept Bitcoin as method of payment ,and do you think they will in the future?
Where exactly did I say that I think that?
8. In your opinion how do you think governments will react with Bitcoin ?
Governments are constantly reacting to Bitcoin in a unpredictable nature. You can easily find this information on Google.
I have not answered this survey.