Airplane can even compete with the sun, so why bother to consider travel time?
That fundamentally depends on the aircraft, and where it is fying.
At the poles, it is trivial to beat the sun and you can do so by walking.
At the equator it is much harder.
"800 kph" is too slow for a long distance flight.
Not by much. The cruising speed isn't much higher than that, and when you account for the slow speed of take-off and landing, and the fact that they don't fly in straight lines to their destination it is reasonable.
Stick to logic. Why going through Seattle?
Already explained.
Not enough people want to fly between those locations to make the flight economically viable.
Even Seattle to Amsterdam is a massive problem for you.
You have been provided with plenty of flights which show your model makes no sense.