I agree with Tartan -- I believe you really want custom quilting. The custom quilter looks at the quilt and makes the quilt stand out in its design. The pantographs just do a design all over regardless of the block patterns.
Your question -- ever taken quilting out --- yes, you can do that -- very carefully. Don't just grab a thread and rip --- that may rip the fabric. And you will have to get more backing. Remember, the longarmer will need more than the quilt top size. You may even need more batting. If you're going to do the new one on your home machine, you don't need the extra. You MAY want to look it over good and see if you can ADD to her design (if there is a design)....