Yes, it will enhance its effectiveness. If you are working on yourself, let's say ALGIZ for protection, you can visualize many ALGIZ Runes around your aura.
Yes. While vibrating the rune, you can visualize the rune in your mind or you can focus on the image of the rune if you have difficulty visualizing it.
what really matters is that you successfully invoke the energy within yourself, depending on the objective and rune used, you can imagine your entire body in a certain color, this helps.
for example, during sowilo vibrations you can imagine gold in you, during ansuz vibrations you can imagine white, and so on.