I'd say, everyone needs to know English, but I wouldn't like if majority switched to English as their only language. In my opinion, other languages help us to learn history of their countries.
Yes. But I would think in the information technology domain, most of the entities don't translate very well. For example words like 'daemon', 'driver', 'segmentation fault' etc. these acquire a certain meaning that just cannot be translated easily to other languages. So you end up with half-half type mix, half of the words in English half in the native language. It ends up sounding silly.
So I hope this doesn't sound insensitive but I would rather everyone learn English, I think it will just make everything a little easier. It is like having a common API between people ;-)