Bronca and Wernicke areas

If Mandarin speakers learn Chinese in a different way compared with English counterparts, then what is the major variation in brain activities? Chinese happens to be a language that uses sound and character separately. If one does not learn the written form, there is no possibility that he knows how to write characters via the pronunciation.

Presumably, Mandarin speakers use both tactile and visual sensory mechanisms to master their mother tongue, but would that help them to acquire other alphabetical languages? Or would it be a hindrance? If one’s linguistic parameter, confined in the area of first language acquisition, had been set long before mastery, how hard would it be to switch the parameter to adapt other languages’ parameters? Or is it just impossible to change?

How much should be sufficient in terms of frequencies of word use so as for an individual to reach the native-like fluency in second language acquisition? How can we manipulate our brains to acquire new linguistic skills so that neurons, be in the Bronca’s or Wernicke’s area? How dissimilar is it in these two areas for both Mandarin and English speakers? What about bilingual people and those who acquire their second language well later in life? Could one use fMRI or PET to sort out some pattern or distinction?

I’m curious about those questions as we know Bronca's area is mainly responsible for outgoing speech, words for speech, and semantic processing or assigning meaning to words, whereas Wernicke's area is linked to memory functions, especially short-term memory, language comprehension, and processing incoming language whether it is speech or written language.