I think it's strange to run with spikes, because you are not used to it, because you usually run with flat shoes, and the contact area between your feet and the ground is large. Suddenly, I can't grasp the center of gravity well. If I wear it a few times casually, I will like the feeling of wearing spikes more and more.
The outermost nail is relatively easy to loosen. I don't think it's because of the word "run" In fact, the strength of that nail is not great during running. As the friend above said, it almost plays a balancing role. Now some spikes don't have that nail, so don't worry too much.
There is no rule about which foot to put in front and which foot to put behind. It depends on your personal preferences and habits. It is the most suitable way for you to start successfully at the fastest speed in the prescribed movements.
I hope my answer is helpful to you.