So back to ethernet wiring - I decided to explore my mechanical room a bit more and climbed up on a ladder to see where the ductwork went. This bulkhead goes across the basement ceiling from one end to my mechanical room.
I can clearly see the joists and so my question is, in a "standard" house, does that mean I could run my ethernet cable all the way down this bulkhead and take a left or right, and be above the wall - then just drill a hole up from the location I want the wallplates to be? The desired spot is about 15 feet away along the wall.
I wish it were simple - I am just not sure how to account for any obstacles that might be hidden.