not sure how I feel about fast travel in a Zelda game...and it being open world is also dangerous
Fast Travel only applies really to anything technological in game so it's still contextualized as working only for Link in universe like it's always been in the Zelda games. In fact, Fast Travel's always been around since OoT and I always made liberal use of it.
In addition, there seems to be a nice amount of space between each fast travel point so there's still some incentive to feel out the world and use other traversal options both to find where to go and to get where you want to go.
Plus, if you actually want to do something like get a horse back to a stable, you cannot fast travel to trivialize the process meaning you do have to keep track of things in the world.
As for the Open world, yeah it is dangerous to do something new but the way they've talked abut developing the game seems to directly tackle the main issue with Open world games in my eyes and that's how the development team has a tendency to not all be on the same page or are unaware of the routing in game which leads to the schizophrenic and poorly paced design that plagues the genre. They've solved both of those issues going by interviews.