Certainly you can do it. Not mention in your country, but also in Chinese speaking countries and regions there are many people who can not write or read, particularly in China. In English world, no offending, it is called ¨illiteracy¨ and I believe such people exist too but they speak fluent, at least, more fluent than someone like me or even English teachers here. As you said it saves you hundreds hours if you just want to practical. If I were in your position I might make the same choice too. if you want a reason to make you more comfortable to make such decision I might offer you one. Chinese is not like English that many science / tech / business research are used as a written language. Without learning Hanzi may lost some fun and art or culture, but it does save you a lot time to spend on oral instead. (Being a native speaker, learning writing Hanzi takes incredible long time from childhood as well.) And the last I know many western people who does not read or write at all but speak fluent Mandarin Chinese. It does not bother them at all because they do not have the necessity to read material in Chinese. What they need is just effective communication without misunderstanding with local people.