You can do it if you are gone direct the movie. If I remember correctly David linch is giving suggestions for: camera movement, Transitions and noise Music.
You are correct that a writer can write the screenplay exactly as
they want: songs, camera directions, sound and music cues, blocking
directions, emotions. It's YOUR screenplay.
Usually here on indietalk writers are asking about the accepted
method. Even if the writer will also be directing it is good to know
and understand the standards and accepted format and methods
of a typical screenplay written on speculation.
Established writer/directors with funding like David Lynch often write
in their own, unique format and style. In general it is poor advice to
look to them as the standard. I always feel it's better to fully understand
how an unproduced, unestablished writer should do it rather than how
an established writer/director has done it in the past.