1. Yes, but they are all so close, for all intents and purposes, they are the same.
2. See #1, and if you were able to feel the difference in steering with the higher trail (you probably won't) the sensation will be gone after riding for 30 min and you'll forget about it.
3. Two name brands, never had trouble with either of their higher end products.
4. Generally speaking, ride characteristics depend more on materials, blade thickness, and amount of offset than on blade shape. Between these two carbon forks I doubt there would be any appreciable differences.
So get the Ritchey, because I always thought Tom was cooler than Keith