This is actually a good question because several people think thatís all there is to it.
To answer your question, no. Simply "imagining" or visualizing energy moving isn't going to do much for you. If it were possible then teenagers everywhere with an over active imagination would be kicking the crap out of people.
Just like any technique from shotokan, shito ryu, tae kwan do or any other external style, there are layers to IMA techniques, chi cultivation and so on.
There are several aspects involved. As stated in a couple other threads you need to understand and use proper structural alignment and be able to transition from one point to another without breaking proper alignment. You need to use chi cultivation exercises and body conditioning that compliments structural alignment and energy flow. Understanding how energy flows and affects the body is important as well as understanding body mechanics. Of course you need focus, intent and visualization. There is a lot more involved than just imagining energy flowing/crashing into or through your opponent.
Of everything it's possible that moving while maintaining alignment may be the most difficult for many to pick up. Some how it's what is overlooked the most by many so called IMA instructors.