Some questions about the Esterel primer...

I'm currently reading the Esterel primer (``The Esterel v5 Language
Primer,'' Version v5 91,
<http://www.esterel-technologies.com/corporate/downloads/primer.pdf>)
and I have some questions...

- p.14 ``As of now, there is no completely satisfactory way of
  unifying the data- flow styles of Lustre and Signal and the control
  flow styles of Esterel and Statecharts. The programming primitives one
  need for data-handling and control-handling are indeed quite
  different.''

  Where can I find more information about these differences?

- ``Reactive systems, also called re ex systems, continuously react to
  stimuli coming from their environment by sending back other stimuli.
  Contrarily to interactive systems, reactive systems are purely input-driven
  and they must react at a pace that is dictated by the environment.
  Process controllers or signal processors are typical reactive systems.''
  ``reactive languages are largely inadequate for interactive
  programming as a whole.''

  I somewhere found a description of Statecharts as ``a modelling
  language for reactive systems,'' and a reference to its use for
  describing ``port-based'' systems, such as described by Modelica.
  One of the problems in this area seems to be that
  Modelica/Statecharts based models cannot cope very well with
  controllers. Is this true? Does this mean that
  Esterel (which _is_ suitable for controllers) would be a better
  choice than pure Modelica to model robot systems (i.e., the dynamics
  _and_ controllers in one integrated modelling language)?

- p.25 ``Valued Signals Versus Variables''
  I learn from this Section that it is not a good idea to make events into
  objects that can carry data: if two processes generate the same event
  but with different data in the ``event object'', this will sooner or
  later lead to indeterministic behaviour because different processes
  will handle the events in different order. Is this a correct conclusion?

Herman