In reply to question iii.
I've never been very happy with the Wikipedia entry on Blondin ropeways. David Gwyn in Gwynedd: Inheriting a Revolution, p.56 writes:-
" A later system was the blondin ropeway, named after Charles Blondin who walked across Niagara Falls on a tightrope in 1852, which was developed in the Scottish stone quarries in the 1870s.John Fyfe installed a blondin at Kenmay quarry in Aberdeenshire in 1872, but they made comparatively little impact, and as late as 1886 only two other quarries in Aberdeen were using them, assisting derrick cranes. They had a lifting capacity of three tons. In 1896 Henderson's of Aberdeen patented a form of blondin cableway which quickly became popular in Gwynedd and elsewhere and which made use of the newly-available light steel ropes, in place of heavy iron ropes or chains. There were differences in detail between those used in the granite quarries of Scotland, in Gwynedd slate quarries and at Delabole, but all made use of the same principle...etc.."
No mention is made of any development at Penrhyn, although it could well be that every quarry that used J.M. Henderson's patented system would seek to modify it to their own particular needs and requirements.
Thus, I would avoid the assertion that Blondins were developed at Penrhyn.