3. Pronunciation, especially the correct production of tonal patterns in spoken language, are a real challenge for non-native speakers of Chinese with first languages without a tonal system. The Chinese tonal system is not impossible to learn but it would help if you had a "musical ear"; if not, it might be a bit more difficult.

It's interesting to note that in the same way some of us English speakers are tone deaf, so are some Chinese people. You'd think that they would have trouble understanding and speaking Chinese but they do not. So, there's some hope for some of us who have given up on the language because we feel we have trouble distinguishing which tone. Also it's possible to understand the mechanics of a language without being able to understand the spoken word, or speak it. Many linguists fit into that category. In fact some linguists understand the workings of some languages far better than the bloke in the street can speak and understand it. I doubt if many ordinary Chinese people realise they are using the right hand part of the brain to process information. I would advise the ordinary FT, tone deaf or not, not to get side-tracked and bogged down with irrelevant details if they want to speak and understand ,Mandarin, in a way that'll be of any use.