are all the stars displayed in the Milky Way accurately placed
All the catalog stars in the Milky Way are accurately placed to the best limit of scientific knowledge. The catalog was generated from data gathered during the Hipparcos mission, the most sensitive astrometric survey mission to date. There will soon be another more capable mission, Gaia, but its data will not be available for several years.
The general rule of thumb is that the closer the star is to Earth, the more accurately it's placed. Procedural stars are neither accurate nor inaccurate obviously, because they don't really exist.
You can easily set what kinds of procedural objects you do and do not see in the program via the F4 menu.