If you need more steps in the arming sequence, do them in the arming routine and call it from setup().
Calling it from the loop runs it over and over and you simply do not know what is working and what is not.
What values did you write later that produced no results?
I see that you write 1400 during the arm sequence. Any particular reason you chose that value? I would have expected 2000 for full throttle which is how most of my ESCs arm. Zero throttle on power up. Wait a bit of time (1 or 2 seconds?) Full throttle for a second or two. Then zero throttle.
Do you have access to a potentiometer? Wire it up like the knob tutorial. Have it write out the values to the serial monitor. Use that to troubleshoot the arming procedure.