That's why I believe the Truthwatcher resonance is involved, as it may allow prediction of future possibilities based on knowledge of the present, which I think is similar to what other kinds of future sight involves. They are seeing into the spiritual realm and using that information to predict the future. However, as I don't know how the surgebinder visions work, I am not entirely sure, but if they use the spiritual realm then the Truthwatcher resonance may help to interpret what they see, thus leading to more powerful visions that "illuminate" the "progression" of the world.
Ultimately I just suspect that the Truthwatcher resonance is more powerful visions. I agree that future sight may come from shardic amplification, as could quite easily be the case for Renarin.
With regard to the honorblade I don't remember seeing anything indicating that Dalinar gave it to anyone, and he may not feel that he should as it doesn't belong to him anyway.