Does skill in art limit an artist, or give him more freedom? That depends on the kind of art. There are many different styles and approaches in today's visual arts, and both, artists and viewers make their own choices in what they like. All styles have a right to exist, yet it's unacceptable to force any one approach on others.
Some directions, such as abstract art, more more on artist's intuition, and do not require a solid set of skills. As oppose to that, capturing a personality of a sitter in a realistic portrait, drawing a realistic figure requires a fundamental set of skills – an academic training. An academic training is a teaching approach that is based on the experience of many generations of artists. It's a system that trains an art student to draw and paint realistically step by step, using a proven method. Academic training is a request that needs to be preserved and built on.
The definition of freedom is having a choice between many possibilities. Yet in today's art schools and colleges, academic training is not taught in depth. Only the surface is scratched, and that inevitably robs students of a choice – what style to choose. Many art students turn to abstraction not because of their personal preference, but because they lack skills to paint any other way.
Being an art professor for many years in an academic setting, I observed how students who mastered the skill of realistic painting varied in their approach. Each had his own way of applying paint, each had his own way of seeing. Mastery of craft did not limit their imagination, but cave them more freedom of expression, allowed them to express exactly what they expected to express.
Thus, I believe that it's a lack of solid foundation that limits an artist, and it's the mastery of skill that allows an artist to soar, expressing his thoughts and feelings, his visions and his spirit.