a) Received Pronunciation is an accent, which pronunciate words as they are spelled. RP . is conceived as a more formal way of speaking.
b) In the 1800’s when a standard English had been established, the upper/upper middle class in the north east of England and especially London, began speaking RP. It spread, and was considered the educated way of speaking, so it became the favorable and more official way of speaking in England.
c) Cockney pronunciate letters, which may or may not be there. For an example ‘hurt’, the ‘h’ isn’t pronuciated. Or arm, where there is an ‘i’ pronunciated before arm. So it would be ‘harm’.
d) Nowadays it’s almost not spoken. Only by the Queen and some elderly people. Just about 5-10% of England speaks it today.
e) The view on RP has definitely changed. Because it’s associated with the queen, the upper class, and the very formal English, people are speaking more and more regional accents. Regional accents are being conceived as a warm and friendlier way of speaking; so today regional accents are spoken by a large majority of England.
f) Today, most people are mixing Regional accents. Meaning that you might mix a Scottish accent, with a Welsh accent. That is what the majority is speaking nowadays.
New Englishes
a) I don’t think Chinese will ever replace English, because English is already so well established in the world. At least for now our tv-shows, our music, and our clothing are from or very influenced by the English American world. Perhaps this might change in the future, but I find it unlikely.
b) Yes, I think it will. There are more native speakers of Spanish or Mandarin, but English is without a doubt the most spoken language. I can imagine a world where is spoken even more than today. Or at least as the official international language.
c) It might because there are so many native speakers of Spanish. I think Spanish in USA will be more spoken, but I also think that English will remain as the main