Condensed phase quantum dynamics

I am really looking forward to this week at the Telluride Science Research Center for the workshop on Condensed Phase Dynamics. (The scenery should be good too!).

In part preparation I re-read a nice review (the 1997 Spiers Memorial Lecture) by Joshua Jortner.

This week I hope I can learn more from others on the big questions in the field, from the perspective of theoretical chemistry.

Here is a random selection of some of my questions, as a physicist. [Cows are spherical but do have udders....].

Note, the focus is on qualitative differences and on "chemical" dynamics of a system in a condensed phase environment, i.e. a quantum system interacting with a large environment.

Can we succinctly state some of the main concepts, organising principles, physical quantities?

The spin boson model describes the coupling of two quantum states in the presence of

an environment seems to capture a wide range of phenomena. (electron transfer, dynamic stokes shifts, competition between different time scales). Are there any cases of a two-state system in a condensed phase where it fails qualitatively? (e.g., because it treats the environment in the harmonic approximation)

When does the quantum nature of the environment lead to qualitative differences in the chemical dynamics?

How does the environment modify dynamics (e.g. internal conversion) associated with a conical intersection between two potential energy surfaces?

Is any progress being made in defining systematically quantum-classical boundary in QM-MM mechanics? Could entanglement measurements provide objective criteria?