Many train designs similar to Class 800 have glass-reinforced fibre (GRP) shapes at the from with the main crush structure a fair bit behind it (usually straight down from the bottom of the windscreen). Main reasons are aerodynamic and general day-to day protection of equipment (e.g. from birds, etc). It also means that in the unfortunate event of a train running into someone/something, the GRP is the thing that gets damaged and not the crash structure (much cheaper).
With regard to safety, all trains will have to meet the required Railway Group Standards (at the time of build) which define a minimum level of crash worthiness regardless of type. In the worst case scenario of a serious derailment, the crash worthiness of newer units will be greater than older units due to the advancements in technology, engineering, manufacturing, etc. This is not to say a Sprinter, etc. is a death trap and you should never ride one because the likelihood of the above scenario happening is very low.
