The only way to have the different tasks update according to their dependencies is to move them. When you create tasks and define dependencies, you need to move the first task so that the others are moved accordingly.
I guess that having dependencies between task Y depending on X means that Y should start after X.
I would really like to see an option where all tasks are autoscheduled like it is the case in MS project. That would avoid to have inconsitency in some tasks in the project.
Making new dependencies should update start times of subsequent tasks without having to move them.
as a Starter, just a button updating the whole schedule depending on dependencies would be just fine.