As far as I know, in that time Arabs didnt have books similar to the ones we have nowadays. There were not even enough papers so sometimes they wrote on animals' skin and sometimes just used their memory. So kitab can mean something written.
If you mean about Moses speaking to God (which I probably think this was the story, though never knew the bush was not consumed), then it was a miracle.
A miracle is : An extraordinary and welcome event that is not explicable by natural or scientific laws and is therefore attributed to a divine agency.
That is what we call "Tawaqqu' al-mustaqbal" predicting the future, and it is haram/Forbidden to do, and the nice thing is they mostly don't work, unless it was a "wild" guess, as some call it.
Though the Prophet (sawa) once predicted future events more than 1 time, and all of them came true, you interested?
Again, if the "angels"(which I think you mean) were to appear they wouldn't appear from their own will, God wants them to appear. Again, God is: the creator and ruler of the universe and source of all moral authority; the supreme being.
So God can basically break the laws, which he himself created, when he wants, as they don't apply to him.
Though angels in Islam aren't the winged angels, they are some sort of "Spirits" of unknown nature. The word "Mala'ika" means the "heavenly" ones, or the ones who always obey. So again not the winges creatures like the Christian/Jewish thoughts.
Though they could possibly lift themselves through the means/ways of aerodynamics. Only God knows.
This one happened, I think it was by Imam Ali ibn Abi Talib (a), he basically puts the amputated part, on the other, and joins them together.
I have seen the name "Allah" once through a cloud, not sure if it is going to help though.
Well, it is pretty hard to do so.