We have old railway lines and canals made into cycle and pedestrian ways only so this is by no means the first, we also have footpaths in residential areas on which cyclists are allowed.
But the problem is where those who do the maintenance have no idea of what it is like to walk or cycle in the area.
Alongside the river Dee from Shotton to Chester the top of the river bank was made into a walking and cycle track. There was a chicane Shotton end, to stop motor vehicles, with a locked gate for maintenance vehicles, and then at the old ferry crossing this
type of barrier, which did not comply with agreed dimensions and so some bikes would not fit, this was a circular route, connecting to the old train track as well, and I have seen groups of cyclists helping a guy get his bike over the bars, as he had a 2-mile ride home one way and a 10-mile ride home in reverse.
Also seen again in Shotton, signs saying enforced cycle way,

this is the optional sign

and then worded signs in English only to say no cycling on the pavement. Since vehicle road also paved, i.e. not a dirt track, clearly person did not understand English never mind Welsh or Polish.
Here in Mid-Wales, the problem is Aramco barriers, being hit by a motor vehicle is always bad, but when trapped between a motor vehicle and Aramco barriers, that's a death sentence, unless cycling and walking not permitted i.e. motorways, or path other side of them, then Aramco barriers should be banned.
The distance we should give cyclists here in Wales is unworkable, with roads far to narrow to pass a cyclist and some common sense is required. Overtaking yes should wait, but when travelling in opposite direction?
In Chester there is an unusable cycle track, due to the drop pavements into properties along the route, so cyclists ride on the road.
Also seen routes where cycles can ride wrong way down one way streets, could see reason, to avoid dangerous roundabout, but no signs warning motorists of on coming cycles.
As to e-bikes, there rules are blurred, like 250 watts on a continuous basis, why the "continuous basis" that means can have a 350 watt motor as long as it does not give out 350 watts throughout the speed range. The throttle depends on age of the bike, they were allowed with early ebikes, then latter ones only up to 4 MPH, so we have a whole range of ebikes, and unless someone goes silly like fitting a 1000 watt motor, we don't know what is permitted with second hand bikes.
The cargo bikes it seems you must peddle it, but no direct link pedals to wheels, peddles drive a generator, and it seems that complies.
Again to allow cargo bikes, the posts shown clearly don't work, so there is no way to physically stop motorbikes.