You can't go back to text you previously written
by which I mean if I wrote: "Today aws a good day", I'd have to delete everything to fix the typo
You have to do some weird-ass key that's on keyboards that no one actually has to do colors and bold and stuff
and they shimmer
1: You don't have to Sign a book to close it. You can go back and write it as much as possible. You can fix them with NBTEdit, but the point is having books people can't edit around with and throw back and forth once you're done.
2: I've heard you can't do those key commands ingame, nor do I believe it was originally 100% intended to do those things. I was the person who added that information to Minecraft Wiki first, you just past the icon thing in and the rest of the coding junk.
3: What's wrong with enchanted books?