Answering to the best of my knowledge, which is a bit rusty, always happy to be corrected by those who know more about it than I do:
The BB is 13. 8 billion years away in all directions. From wherever you are in the universe. It's a precise event, not an imaginary horizon that shifts forward as you approach it
Not sure about the "precisely", but in that ballpark. Not hundreds of billions of years in any case, and not thousands of years, either
The universe is flat, and expanding, not curved. Time and space etc, don't just seem to originate at the BB. They do originate at the BB.
I thought actually, we don't know the sign of the curvature, measurements being close to 0, could be either side, or spot on...
Energy, time and space and the four forces + gravity originated 13.8 billion years ago. Precisely.
Well, gravity is one of the four in fact. Gravity, Electromagnetic, Strong, and Weak forces.
A black hole singularity is a result of matter being compressed to infinite density. It has a cause.
Not infinite density, no, but in an interesting state nonetheless.
The event horizon is the defining feature of a black hole. In a sense, the "cause" of a black hole is the speed of light and the gravitational constant, which determine the Schwarzschild Radius of a mass. A funny way to put it is: If the escape velocity required to get away from a star is greater than the speed of light, then you can't escape it any more.
Of course, there is a lot more interesting stuff going on with black holes, especially with respect to the conservation laws, across the event horizon.
'Since the beginning of time,' used to mean 'forever.' Now it means 13.8 billion years ago.
Everything going down the drain. Not even time is as it used to be