Running

The length of time it takes to run a half marathon means you need to be able to....

... take on carbs and fluid while running.

I think you can do the distance without that (I've run 10 miles with no refreshment), but that would limit the speed you could do it in.

Get the right shoes

I aim to run a half marathon (or, at least, a half marathon distance) barefoot, this year. Really silly ambition, but achievable.

Health destroyer? That sounds terrifying. I would be more worried if it wasn't so far away. I've just got to make sure that I actually get started now.

Full marathon can be - certainly much, much more physically punishing than a half marathon. Luckily, you're attempting the latter. Like I said, this is achievable simply from a decent level of fitness, without any super special training or technique.