If a 395 runs late, the driver just puts his/her 'foot' down. There seems to be quite a large recover time in the timetable.
For the tunnel itself, is there are restriction on the number of passengers that can be in there at any time (for evacuation purposes), or the length of the train or similar?
If other operators started to run services, would there be a market for a very low-cost service, starting at each end of the tunnel, where you do away with a lot of the luxuries and squeeze in 3+2 seating, less luggage space and just use it to shunt people from one country to another.
395s could then start taking international passengers, where people then board to effectively squeeze in to a train to go through the tunnel and on to other services in France. If we signed up to the Schengen Agreement, it would be even better!
Clearly the tunnel is the weakest link, given that it has to allow vehicles and freight through it too.
I don't know what the capacity issues are on the French side. Mind you, I can see that they could quite easily expand as necessary, and quicker too.