Both are correct if you keep the "will" in the second one. The first is slightly informal, the second is more formal and would probably be used in a legal setting or in an official letter of some kind.

Yes, it is correct!

Both are correct grammatically, but number 1 is probably what you are looking for. It says that the boss is still waiting for the return call. Number 2, past tense, is saying that the boss had wanted you to return his call before. However, in spoken English, you will hear these sometimes used interchangeably. The way I would naturally write or say the sentence would be "The boss just called and he wants you to call him back."

спасибо Alex!

This is more or less a literary term (you would rarely hear a sentence spoken like this), it is a more artistic adjective for describing what the shadows look like. In this case, the author probably means the shadows were very well formed on the ground and were very pronounced. In other words, it was a strong shadow, not a soft shadow.

The only one that seems natural would be outbreak. Outbreak (or for a more severe case, "epidemic") is usually used for a disease.

здесь!

You are correct. Depending on what the person is trying to say, the first sentence should be "Why do you do this?" or "Why are you doing this?" or "Why did you do this?" (past tense). Second sentence should be "Why do you have to do this?" depending on the tense. Often in fast English, native speakers might say the last sentence like "Why'd you have to do this?" which may sound the same as "Why you have to do this?", especially for certain accents.