On Life & Death (or serious injury)

 Read almost anything on the internet on 30 mph mopeds and you'll quickly be convinced that they are dangerous. You will come away assuming that anyone riding one has a life expectancy measured in minutes.

Is this really the case? If it is, then why are they allowed on the roads of the UK?

I haven't got access to collision statistics - if they exist separately for 30 mph restricted machines - if you do have then I'd love to see a link in the comments.
What I do have is - as noted in earlier posts - a vast experience of cycling, and a number of years experience of casual motorcycling (and slightly more as a car driver).

There are a number of interesting comments made by "Teflon-Mike" in the BCF Forum at https://www.bikechatforums.com/viewtopic.php?t=299314&postdays=0&postorder=asc&start=50  and I've drawn on these comments extensively to shape my thinking.

A two wheel rider in Britain faces - in my opinion - two main dangers : vehicles turning in front of them, and being 'rear ended'.
I have experienced the former on both a motorcycle and bicycle, and have frequently had 'close passes' on a bicycle that put me in retrospective fear of being 'rear ended'. 

By vehicles 'turning in front' I mean both cars (etc) turning out of a side road into the path of the two wheeler, and also being 'left hooked' where a car (usually) overtakes and then immediately turns left. 

Vehicles turning into the path of a cyclist or motorcyclist is potentially fatal, as the rider is likely to go over the top of the turning vehicle. Such a collision is generally caused, as far as I can see, by the driver not seeing the bike - or perhaps more accurately, not 'registering' the bike - the driver may look in the direction of the bike, not see what they expect to see, and proceed anyway - bang!  The driver looks but does not see.

There is only so much a rider can do to prevent this type of collision as far as I can tell.
Road positioning is important, as is making the bike and rider visible against the 'noise' of the road environment. This visibility can be by use of clothing or lights.
On a bicycle I am convinced that a flashing white front light does more than any clothing ever can; on a motorcycle there is more scope for changing road position, and with a constant headlight. So-called 'high visibility clothing' may well help as well.
As a car driver I find fluorescent helmets and gloves effective on a motorbike rider (however unfashionable). 

The left hook is simply dangerous and inconsiderate driving. It happens to cyclists and I do not think (from the luxury of my armchair) it will be a danger on my eMoped - unless a driver seriously underestimates the speed at which the machine is travelling. It's hard to predict, but with road positioning and judicious use of mirrors it should be avoidable to a large extent.

Being hit from behind is a close cousin to the close passes that cyclists experience.
I am not convinced that many motorcyclists are hit from behind other than in very slow traffic, if ever.
Close passing of cyclists is born of lack of empathy for what it is like on two wheels, and there may be occasional aggressive close passing. It is unacceptable.
I suspect that at 28mph I may start to experience close passes on my NUI. I may also get aggressive tailgating - a prelude to being 'rear ended' perhaps? 
These fears have, to a large extent, come from the experience of riding my Tomos moped which I referred to in an earlier post. The NIU UQI GT Pro has much better acceleration, and the top speed should actually be achievable in less than a fortnight - so hopefully these worries will be groundless.

Close passes and tailgating are my main fears of life at 28 mph. Both should be manageable by road positioning and 'taking the lane'. Hopefully!

'Teflon-Mike' makes a useful distinction between Safety and Comfort.
Some things are safe and uncomfortable (he says riding a motorbike on a major dual carriageway), some things are unsafe and comfortable (he says riding on suburban streets).
So we have a matrix of safe/unsafe & comfortable/uncomfortable with unsafe & uncomfortable being the worst possible situation. For me, locally, I suspect that the psuedo-motorway, dual carriageway which is a feeder for the M1, may fall in this category (and I'm not intending to test it out); safe & comfortable might be a lightly used country lane with good sight lines. We shall see,

Human nature says that if it feels uncomfortable then it must be unsafe (and the reverse). I am not sure that is always true on the roads.
I have cycled on roads that feel uncomfortable due to the presence of HGVs and too much car traffic, but where I have never heard of a collision involving a cyclist. Equally I have cycled on lovely country lanes and encountered aggressive car and lorry drivers apparently determined to injure me.

There are separate, but similar, issues associated with riding in the dark. I may muse on those at another time.

I will pick my routes for my NIU with care, and I will be riding with my headlight on, and I will be wearing a 'hi vis' jacket (with panels of both lemon & orange). 
I will be fascinated to watch how my fears of tailgating (in particular) and close passing play out over the months - I will try to keep you posted.