These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
The film was considered so incomprehensible by the studio that they made Lynch include a set of clues to the plot in the initial DVD release. Unfortunately, they made Lynch write the clues — and he wrote them in such a way as to heap even more fuel on the fire of Wild Mass Guessing.