no, very good points... actually are there any ways of sealing off each carriage?
UNfortunately we need a big incident like what you have described to prove to the people with the purse strings that conductors are required
They do indeed have barriers to block off gangways between coaches. They also have quite an advanced smoke extraction system. These wouldn't help in the event of a bomb (or, probably, a particularly hot and/or rapid spread of flames) but then that would apply to quite a lot of other trains in other ways anyway.
I really don't want to have to dig out the DOO debate on this thread - really, I don't - but despite the low overall likelihood, I wonder how quickly passengers could be shepherded by just the driver and potentially a handful of PTS-trained station staff, when they can see pretty much from one end of a train to the other, and thus quickly see any fire even if it doesn't immediately affect them, which could well induce more panic. Someone who does not have to walk from the driver's cab or a station would surely be better-placed to assist quickly in such a scenario (though I'd hope there would also be thought into providing equipment to protect the line at intermediate positions on the train, such as track circuit clips, in order that lines can be blocked before an emergency evacuation without heading to a cab). I also wonder how quickly the inter-coach barriers could be used in real-life operation. But on the plus side, I can see that passengers are probably less likely to exit onto the track and more likely to stay onboard and walk/run down the inside of the train if there are no gangway doors.