Hello, I'd like to point you to the local tagging guide for Canada and the guideline for abbreviations in OSM.
The "St. " in St. John's in fact correct and not to be expanded.

osm.wiki/Canada/Tagging_guidelines#Municipality_Names

osm.wiki/Abbreviations#Canada

Could you please revert this?

It's up to you, I have no strong feelings either way.

>What was the point of that?
This area is covered in grass. I hindsight, the appropriate tag would be surface=grass but this was from a time when I was new to OSM.

>why this area looks different than all other areas
I didn't want to commit to adding this level of detail to the entire city. I was using it like a personal testing ground for different tags and methods.