The erosion from Bwlch y Saethau, up the side of Snowdon on the upper reaches of the Watkin Path, is a problem that the Park authorities can do nothing about, and it is considerably more hazardous than the scree ascending Glyder Fawr from Llyn Y Cwn, especially in winter.
Yr Lliwedd is a very straight forward mountain, and offers no problems for the keen walker wanting to attempt Snowdon from the opposite direction.
There is no extreme exposure on the summit of Lliwedd, unlike its neighbour Crib Goch, which is a totally different proposition.
The scramble up the Gribyn ridge below Glyder Fawr, is straight forward, and perfectly safe, offering no problems in ascent or decent.
It can look a bit intimidating, but there is a clearly defined path that you can follow, once you gain the ridge itself.
The Gribyn above Llyn Glas, below Snowdon, is a grade 1 scramble, and i have not attempted it.
The rest of the list, i am sorry, i cannot offer any advice on.