Well, languages are incredibly geographical. Even though all the Americans speak the same "English", you wouldn't call what a New Yorker says is exactly the same as what a Alabamian says, right? And if you tried to mention your idea of distilling all languages into one giant one to any decent linguist, you'll probably be shot in the head at least 3 times. Lingualnomics which rhythms genomics, will probably take a bigger database and a faster computer than mapping the simple 4 base pairs and its combinations.
If a child is exposed to a multilingual environment at a young age, he/she has a higher chance of recruiting more neuron clusters to the speech "area" required to process such things. But that doesn't mean it's impossible, during my 5 years of immigration practise, I have been proven wrong a lot of times by new immigrants who seem to struggle with ESL. Language is like many things in life, which is a skill that goes hand in hand with habits. Any speech or writing quirks that you have is probably the result of things that happened during your development phase that get ingrained with emotional weight without you realizing it.
As for the "official language" business, that has to do with politics, not linguistics. Canada's desire to require 2 "official languages" makes a lot of things quite complicated. It's like a country with a cultural split personality. If you are/speak French, you can probably stay in Quebec' or PEI all your life and never have to learn English at all. People in the West Coast, like us, has enough to deal with as it is, i.e. Chinese, Japanese, or Korean, all the while wondering why we are legally required to print things in French when most of the people/consumers of our products don't speak it. French student get more funding for their "special" schools(French immersion) while a lot of "regular" schools struggle with provincial funding with the Federal government looking on to protect their resource industry and wondering why it's not 1908.
Anyway, ranting aside, if there is enough demand for it, things will eventually happen. I actually considered learning Spanish in high school simply because of usage. English, Chinese and Spanish are probably 3 of the most spoken languages around according my knowledge back then. I also wanted to learn Japanese, and Italian, but that was for personal interest, not because of the fact that a lot of people speak it.
It also goes back to my original idea that the bigger the minority community is in the local area, the more likely of the fact that there would be a lot of "home" language in the area. Rational Segregation argument aside, that's how it is.
As for the fitting in/integration argument, that's a difficult topic in the immigration circle with the usual debate ending up in name calling, racial slurs, and huge flame wars. For my view, it takes 3 generations to be fully integrated into a new culture/country. If you don't believe that, go live/work in a totally different culture/country compared to yours for long periods of time and come back and talk to me. China, for example.
I have taught ESL for more than 10 years now, and I have seen more immigrants than probably stars in the sky. The difficulty, the fear, the regret, the xenophobia, the let down, the loneliness and ultimately, the desire to fit it but not being able to are the hurdles most immigrants have to go through to start a new beginning and a claw out a new life for themselves. Nobody really wants to be isolated from the society at large. I have had that feeling before, and it's like you are a movie camera(since you don't really exist) watching and filming life passes you by while have absolutely nothing to do with you(since you can't seem to effect/affect it in any way, shape or form). Most people want to fit in, in some shape or form, so if we make it easier, maybe we wouldn't need the special signs.
P.S: To my knowledge, there are no Chinese road signs in Vancouver(I can't recall whether China Town had them or not, but if it did, it's probably for tourism reasons), despite the fact that they are the largest minority groups around here. It's probably too expensive to print signs in non-Latin anyway. Not to mention the fact that if anyone tried to print any simplified Chinese road signs outside of China will have to meet the Starseeker's squads of chainsaw wielding Battle Sisters that burns all attempts at a fake language outside its own country.
