What was your logic on making this change?

While it is a dual carrageway with one limited access entrance/exit at the dump. It does not meet the functional standards of a motorway. Nor does it meet the OSM convention on highway connectivity.

Those sound like reasonable criteria. It has been a while since I walked the area that caught my eye in your changeset. It does look like they have added center lines to some of those streets since I last looked.

What is the criteria you are using to "deepen" road classifications? I am not in agreement with you on some of these changes so I’d like to understand this.

I think that, in general, parens should not be used in names. For each of these locations, I'd put the primary version by itself in the name field and the version you have in parens as an alt_name value.

I looked to see if there were ISO language codes for Acjachemen, Luiseño, or Tongva but apparently there are not. If there were, then the primary name should also be put in a name:isocode field.

The way would be way/1377679079

People have hiked all over these hills and there are at least some published descriptions of hikes from PMC to the top of Mt Pinos, Sawmill & Grouse. But those are, at best, routes rather than trails.

I harbor a strong suspicion that your route up from the trail into Wind Wolves to the old 4x4 track on the top of the ridge falls into that same category.