There are at least 15 fields one need to be mastered before one can authoritatively interpret the Quran. Read more here in the methodology http://en.wikipedia.org/wiki/Tafsir

As far as reading is concerned , everyone reads it in Arabic, remembers in Arabic, millions from different countries and different age group remembers it. One of my family member memorised it in just 9 months and can recite it without a single mistake from start to finish.

As per my calculations with the available statistics, at least 10 million muslims today has memorised it completely.