I'm not sure 100% but i'll have a go:
1. I would say no because it is a chariot, it just has move 10.
2. MR doesn't work against miscasts, just spells cast at the unit. In the same manner MR does not help against like magical weapons or magical attacks (i.e. enscrolled weapons, daemonic attacks, etc.) The only thing that I can think of works against miscasts that would be considered magical protection is the Banner of the World Dragon
3. He would use the the model in front of him's line of sight. In the rulebook it talks about drawing line of sight from the front rank, so I would assume this would qualify as that.
That is what I think at least, others might have different interpretations.