1. If the ally Jonathan Harker is played, the entire Dracula's Trail is revealed(including his actual position), right?

2.If a hunter encounters Rats, he must roll four times the dice, right?

1: Not the entire track but the SIXTH card to the Dracula's right (so it will be the oldes card, and only that one card)

2: Yes, if a hunter encounters the rats then he have to roll four times, so if he have a bad luck he can loose 4 life in total.

Many thanks Jervon, from now I will read the cards more carefully:)