Nice contribution! Sometimes printed material can get things wrong, or be out of date: OSM uses "what's on the ground".

I know this region is was originally sold as Ranelagh Estate back in 1924, and is listed in both the Victorian Heritage Registrar and National Trust of Victoria, as well as parts being listed in the Heritage overlay.

OSM follows the principle to map "what's on the ground". There's nothing on the ground that calls this region Ranelagh Estate, nor does it appear in maps or vicplan surveys as Ranelagh Estate, so I'm not sure name= is an appropriate tag. There's a historical information board near the John Thomas memorial, but no signposts or indications you're entering anything special except just another suburb.

I've wanted to somehow map the historial/heritage information about Mt Eliza/Ranelagh on OSM, but I don't know how other people have mapped heritage or historial land areas. (Perhaps this should be discussed on the osm-au mailing list?)

There's a lot of historical information if you google for a document called "Ranelagh-Conservation-Management-Plan-July-2009.pdf"

Great work.

Are these cycleway:left=track or cycleway:left=lane? It's unusual to see cycleways as seperated tracks in Melbourne, whereas it's much more common to see them as afterthought lanes.

Nice addition! Consider adding smoothness= tags too, which helps with hiking/bicycling gps routing devices

Is this the name of the building, or the organisation working within the building? If the latter it may be better served with a node inside for the organisation, and leaving the name of the building blank.
(The building might have a name like Training #1?)

Really?

Great work!

Is the strava heatmap a permissive/legal/allowed data source unencumbered with licensing?