Anton wrote:
"For me i dont want to learn kasar indo as learning from scratch gives you the chance to learn it as it should be spoken it may be boring to those who prefer to speak only slang but im sure many indonesians would respect a foreigner for learning their language it its correct national form you could still learn other dialects if you choose"
Sorry Anton, but speaking only formal Indonesian will only achieve isolating yourself from many and most conversations amongst locals
If you wish to connect with Indonesians through language, you must be able to converse in either their dialect fluently (for example, in Central Java Indonesians tend to speak very refined Javanese and very little Indonesian, when conversing amongst themselves), or be able to speak "marketplace" Indonesian - which is not a "slang" version or Bahasa Indonesia, but more-so a colloquial version. Most Indonesians converse amongst themselves in a mixture of "marketplace Indonesian" and their own dialect (be it Balinese, Javanese, Sundanese, etc). When they travel or converse with other Indonesians who do not speak their own dialect, they revert to pure "marketplace" Indonesian, and generally not Bahasa Indonesia.
When an official is interviewed or a reporter reads the news, they are speaking Bahasa Indonesia - that language, will be fine if you plan on doing all the talking, because yes, most Indonesians understand it - but if that's all you speak and understand, the person you are speaking to will need to answer you in a language that they would only otherwise speak in a very formal setting (e.g. Perhaps being interviewed). And as a participant in a casual conversation with a group of Indonesians, you'll understand but a mere fraction of what is being said (unless you don't mind making everyone speak Bahasa Indonesia for the benefit of yourself).
As for being respected for making the effort to "learn their language", as Tintin alluded to, most Indonesians see their own dialect as their language and formal Bahasa Indonesian as the written / media language.
Troy F.