that's it?
that is absolutely not grounds for immediate eviction IMO.
There had been no periodic inspection and testing of the electrical installations
A periodic inspection can be arranged inside a few days for a few hundred quid.
The building had no lightning protection system
I doubt it's needed, and I doubt the fire safety guy has expertise in that field anyway, so I'd get a report from an actual lightning protection expert, then get a system fitted if they recommend it, I'd expect it to be under a grand.
Basic security against arson from outside was unreasonable
wtf does this even mean? If someone wants to commit arson to burn a building down then they've find a way to do it. But if there's more detail about the concerns then this shouldn't be too hard to resolve.
"that the present level of compartmentation provided by the walls ceilings and doors would not confine a fire to the room or floor of origin and would very quickly compromise the escape stairwell and render it untenable. The restricted access for fire fighting appliances compounds this problem."
As long as the walls, doors and ceiling on the stairwell are in good condition, they should provide around 20 minute fire protection, as per guidance quoted earlier in the thread - if not in good repair, then a plasterer can sort that out in half a day for £100-150.
There would then be a variety of options to resolve these concerns, not just the 30 minute compartmentalisation standard - alternatives would be enhanced fire detection system, so heat sensors in each kitchen on a centrally linked fire alarm/detection system. Fire doors on different levels of the stairwell would also help to improve the situation in terms of compartmentalising the building.
Essentially they appear to be applying the letter of the regulations for new build, rather than finding suitable solutions to the problem as per the guidance for historic buildings, so they seem to be working in breach of the official government guidance as an alternative report from someone who specialises in historic buildings would no doubt confirm.
If someone sends me a copy of this report, I would be happy to draft a response to it over the weekend. pm me for my email addy, or upload the file to a filesharing site etc please.