Use the map you like, it is a matter of taste. OSM has loads of dirt tracks. Tracks are rated on a scale from 1 to 5 (google 'osm tracktype'), that rating is appended to the track names. There is also a smoothness rating (google 'osm smoothness'), that rating is also appended to the track name. Observe that a smoothness rating of 'impassable' might be what an off-roader calls 'technical'. Grade 1 and 2 tracks are shown as a solid brown line, (same line is also used for unpaved residential roads). Grade 3 to 5 tracks are shown as a dashed line. You also have something called paths, in Thailand that is often used to represent single tracks. Motorcycle paths are showns as a dotted brown line. This is map is motorcyclists, that means that it will not route on roads where motorcycles are banned, like motorways around Bangkok. The estimated max speed is set to about 90 km/h. Anything you add will show up on all maps made from OSM data. Yes it is possible to add fake tracks. It is not a problem at the moment, the errors that exist usually comes from the use of old satelite images. This version does not have an OSX installer.
