So many questions, far too much time on my hands...
Training: They should familiarise themselves with the contents of the risk assessment. Just reading through it properly might shed some light on things they might not have understood. (provided it is done to a reasonable standard) As far as actual training goes, in this sort of instance I would suggest having good procedures in place, so they know exactly what they will do if there is a fire. i.e. Raise alarm, phone 999, attempt to help guests out if required, location of assembly point)
Extinguisher familiarisation always helps, hands on training is clearly better, I am sure you could help them with that one.
If they have guests that are willing to take part in a drill then they might aswell take advantage of that, otherwise I am sure that discussing what they will do between themselves would suffice. RRO does say that drills should be done, but this could be quite informal in this instance. (A couple of "fire action" notices dotted about are a constant reminder to them what should be done, in fact stick one on the back of the toilet door, you have a captive audience.
)
What we really need to avoid is the pandemonium that tends to happen when something like a fire happens and people do not know what to do.
The owners safety does have to be taken into account under the RRO. Their private part of the building
should be classed as domestic, however they ARE relevant persons and that means they still need protecting from a fire in the rest of the building. (which the new alarm system should do quite adequately provided they have sounders in their part)
If we can class their bedroom and the kitchen as domestic then the kitchen door scenario isn't as bad as it might sound. Look at any studio apartment, you are sleeping in the same room as the kitchen. Provided they do not have to travel through or past the kitchen to escape this could be easily covered by grade D smoke detection in the escape route. (If it is truly domestic then we can't require anything, but they should really have some form of detection for their own sake)
As far as DDA goes, you/they are expected to make 'reasonable adjustments' to accommodate disabled persons.
