How do you know that I have no knowledge of this? I used to live in Thailand for several years, and have been to many parts of Malaysia on many different occasions.

Incorrect.

Please refrain from discussing subjects which you know nothing about.

Yes, it is; though, the politically correct term is the "developing country."

Kuala Lumpur may be prosperous, but if you look at the "whole" country (and don't forget to include the piece of Malaysia on Boeneo Island), then that country is still developing.

Yes
Even though they hsve ome modern cities much of the country lives in rural areas without dependable electricsl service or clean water