It means "what are you....." Whatcha doing, whatcha watching

It means "do you"

It means "do you"

In the UK whatcha is also used as a slang replacement for hi.

Ahh being from the Southern United States I can answer this. D'ya is short or slang for Do you. Kind of like Y'all = You all or You all come back now ya(you) hear? That is very grammatically wrong but how some Southerners talk haha