Are phrases like "Hungry kya?" and "She look sad?", spoken by people whose first language is not English, actually 'wrong'?

I'd say they are correct. English has always been in a state of evolution - and I'd agree with this newsweek article that the latest stage is all abotu how Engliah is changing through being used internationally.

Is the only 'incorrect' English ambiguous English?

I do believe it is currently wrong, but many of the things we currently consider right were once thought incorrect, so they may become correct in the future.

Sure.
No one speaks the Queen's English as it used to be now.
What with a schedule (sh-eh-dd-yool) being a schedule (skehdyul) now and all the silent t's we were taught being redundant. For instance often is pronounced along with the t sound.
Plus so many foreign words are streaming into it such as kudos, kismet, karma, and so on.
Yet, I feel it is best if we speak it as properly as possible and maintain the respect; contrary to what is being popularised by net lingo.

HOpe I wasn't too much of a moutfhul,
Adues,
an anarchist called Pin~Jinx

It is the very fact that English is used to communicate worldwide that preserves it and stops local dialects of it getting established. This is true of England itself. A good example is our comedian Lenny Henry , who jokes about it. He was of West Indian immigrant parents but they lived in Dudley, in the industrial area of the West Midlands. As a boy he was speaking 'West Indian' to his mother as he went to the door to meet his schoolfriends but talking pure 'Dudley' to them; sometimes he was literally using one to say goodbye to his mother and saying hello to his friend in the other whilst still standing on the doorstep , to the surprise of both hearers.So he was bi-lingual in accent and dialect. But in his speech as an adult, whilst he can still do both , he uses standard English with a light Midlands accent. His generation grew up to be close to mainstream English. They learned, by exposure, to adopt a language that is readily understood in general because there are no pockets , no small communities, in which they spend their lives talking only to like speakers.

The result is that children in Dudley now talk with less of the accent and far fewer dialect words and expressions than their great grandparents and grandparents do or did.

As the dialect speakers in the other places mentioned progress to communicating more widely their dialect shall weaken and die too. However many of the words and phrases may survive, simply because they are useful and suit a need in the wider world. It would be naive to think otherwise