Routing is only as good as the data it is run off from. To do routing correctly for cars, you need direction of segments (one way, two way, only certain kinds of traffic like cars vs trucks, etc), some way to measure the cost it takes to transition the segment (like speed), in some cases number of lanes for "bear right or stay left type of directions" and even more difficult, z level connectivity (for example the Bay Bridge in SF has a set of segments that go above in one direction and another set of segments that go below - exactly in the same direction - right on top of each other).
Sure, yes. OSM has more of that data for cycling than anyone else; that's why I said OSM cycle routing is better than Google's. It's not there for cars yet (more OSMers survey by bike than by car), but all the things you mention are in the OSM data model, and all but number of lanes are commonly tagged in the best-mapped countries. It'll come in time.
Search for Navstreets Reference Manual for an example of Navteq's complicated schema for routing: https://www.google.com/search?q=navstreets+reference+manual
I really wish OSM was good enough for those two things... right now, it is not there yet.