Pourquoi il y a access=no?

Skitour should be reserved to paths.

Yes, I did see that I needed to provide attribution, but didn't really know where and how. I thought it was only when used in an application.

Noted for the first comment. As for the 2nd comment, not sure what you're referring to?

Les steps y sont, non ? Voir : way/1421368719

I forgot the note #, but what is the usual practice? Should I tag the note URL ?

J'ai vu, je suis en train de remettre en question si c'est la meilleure façon de faire considérant la description de wiki OSM.

Wouldn't be better to tag it as a track? From a cycling perspective, I can't say that a route like Petit Train du Nord or Canal Lachine is the same as a cycleway near a road (REV). There should be a distinction between 100% cycleways and cycleways on the side of the street. From a cyclist perspective, it's nice to see where I can go on a ride on a road without cars. That's my 2 cents.

Here's how cycletrack is defined : A cycle track is separated from the road by curbs, parking lots, grass verges, trees, bollards or another physical barrier, but is running parallel and next to the road. In North America this is called a protected bike lane, separated bike lane, greenway, green lane, or class IV facility

cycleway=*#Common_values

It didn't show on the Google Maps street view or mapillary. So this should be : add cycleway=separat?