Hey Robert,
That is actually what I was thinking when I wrote the jomsocial plugin. Why would I ever want to share my address with the world on a website
But I never actually came to the idea to use just the city and country for the geocoding. Right now you'll have to hack the code in order for it to use just city and country (which is not that hard). In the next alpha release for hotspots I'll add the option to select which parts of the address to use for the geocoding.
About k2 - I've already made several changes to the plugin - you are now able to enter the address on the map, which will save a lot of geocoding issues. (but it is in the hotspots 4.0 alpha 2..., not in 3.6.2)
What are you actually trying to achieve?