grammaticality - "Why you no...?" or "What that no...?" — are those grammatically correct?

None of them is grammatically correct. They should be:

Why {don't / didn't} you come?
Why {aren't / weren't} you speaking English?

or

Why {don't /didn't} you speak English?
Why {don't / didn't} you have a girlfriend?

I offer past and present tense choices because there's no context to tell me whether they refer to the present or the past.

Also, there is never a space between the last word in a question and the question mark.

The kind of English you ask about is possibly either a pidgin or a stereotype of how people who speak pidgin English sound. This is common in old "cowboy and Indian" movies about the American west and other English-language movies with characters who aren't fluent English speakers, especially characters who might live in jungles, in grass huts, or in caves.