Part 2 of 2

3. Does it really matter what kind of English accent you speak with in the UK? Does it have a vital influence on what kind of job you might be able to get or evan decide what kind of social class you belong to in people's eyes?
Yes your accent is an indication not only of what part of the country you are from, but also your social background. Less so than it used to be, but still it does indicate social background. Some accents are considered not very nice to listen to, for example, the Birmingham, Manchester and Liverpool accents. I don't agree that most English people don't care about class. Class issues are embedded in British society and it is still a big deal for a lot of people, especially working class people for whom it is almost like a badge of honour. Some people also want to attain middle class status having come from working class backgrounds, and accent is a part of conveying that. I'd like to say accent doesn't influence the types of jobs you can get, but sadly I don't believe we have quite reached that point yet.
4. I also know that the RP accent is mostly used in BBC broadcasts and is considered to be a sign of a good education. Why does the video give me a totolly different feeling?
As I hinted at before, the accents of people on the BBC are not the 'true' RP. If you can, find videos of BBC newsreaders from 50 or 60 years ago, and you will hear the accent which I believe the person has a particular distaste for. That accent still has connotations of elitism.

Part 1 of 2

I don't like it, although I should qualify that remark.

The RP accent is now rare within the UK. Many newsreaders don't have what I consider a true RP accent, most people on the BBC have regional accents, but spoken well and clearly. Perhaps they can be considered to speak with a 'relaxed' form of received pronunciation, but when I think of RP, I think of that horrible elitist accent that newsreaders and announcers used to have 50-60 years ago.

1. How do they think about native speakers speaking in an RP accent? 

Well like I said, I don't like the true RP accent. The UK had a class system for many years, and for a long time if you didn't have an RP accent you were at a disadvantage. It's not even the accent I dislike, more what it used to represent. 

2. How do they think about people who speak English as their second language speaking in RP accent?

Well, as much as foreigners might think they have an RP accent, it's highly unlikely they do so it's not really a big deal. You can't really have an RP accent if you have first language interference in your accent. Just try and pronounce the words clearly, if imitating the RP accent helps you to do that, then do it.

Thanks for your answer. I just never thought that accent could make such a difference in UK. In China, it's like people all speak Madarin carrying some accents based on different regions, but it's not that important when it comes to your job, your social class or your background.

http://www.theguardian.com/society/2015/jun/15/poshness-tests-block-working-class-applicants-at-top-companies

This is an article from two weeks ago. I would love to say people will not judge you on your accent or background in the UK, but like I said we aren't there yet.

Thanks for letting me know your opinion because for me RP is an accent that I consider easier for me to understand and imitate. But in the morning, I just happened to watch this video on the internet which kind of like gave me a huge hit on head. If people in UK really feel like people talking in RP accent like an old man, that can be a big concern for me.