1. A path?

2. There was a stone that said G3, G is the first letter of the name Gandalf, and 3 could either mean the third of October or the day that was three days ago. Anyways, they are the same day so it doesn't really matter. ;-;

3. Frodo could now see clearly what the Black Riders really looked like.

4. The effect of the wound is that if he is not kept warm, shall he freeze to death. The wound will give in just a deadly chill, not exactly deadly though. The knife was probably an Ice Blade.

5. They might be weak against water, and the river was probably magical and deadly to those who are not welcome.

6. Do you mean by relatively, or in the book? If you mean in the book, he got separated when that white horse ran off. If you mean relatively, like the similarities and the differences, then I do not know.

7. He would have faded away.

8. He was captured by Sauron's sidekick, an ex-friend of Gandalf. That would probably be in the dream that Frodo had earlier.

9. I have no comment.

10. The Nazgul is simply another name for the Black Riders, or the Ringwraiths.