However I'm curious if 1) folks have a sense of the long-term permanence of existing regulations in these cities; and 2) if there are other locations in Denver metro that are unregulated currently but could trend toward investor friendly like Arvada and Wheat Ridge (and Littleton which is out of my budget).

The houses are located near public transportation too - most of the occupants don't have cars. 

Check out local economic development websites and job boards to get a sense of the employment opportunities in the area.Consider the location: Think about the neighborhood's proximity to important amenities like shopping, restaurants, and public transportation.

At this point it is largely unregulated but that's all on the table right now. 

Other things come into play like plans for public transport like rail cars or the like, things that would create a need for parking lots or garages. 

Especially if they are claiming they do not need a license and are unregulated by the state.

Transportation, insurance, etc?

Its still way behind rent, food, transportation...

Some crashpads provide transportation, but that usually involves a full-time tenant living at the premises providing on-demand pick ups and drop offs.

Brooklyn is most attractive because of its proximity to Manhattan, access to public transportation, restaurants, and other attractions.