I agree with the your view on competition, or at least some active resistance in sparring. You don't have to go all out to test your techniques. You definitely need some active resistance and attempts to counter or stifle your techniques. This is where Aikido draws a lot of flack from outsiders. The compliant partner practice comes under attack because those who never progress beyond it, assume what will work and wont under resistance.
How does this relate to intimidation? Well, if you tussle around with actively resisting or attacking uke, or competitors in say Judo or other systems, you have the confidence to know, what your high percentage techniques are, and which ones you will stay away from. In short, you have a solid game plan complete with audibles for the what ifs. You are sure in your techniques and have tested them. When you have someone bringing the potential for physical confrontation to you, you are less likely to be uncertain of yourself and therefore be less likely to be intimidated.