i don't believe there is any (CHEATing) about quilting- just because you used a PANAL-does not mean you CHEATED!
most of us use printed fabrics of some sort--doesn't make a difference if it's a PANAL or if it's an all over print.
as for trimming/squaring-
i usually try to line up an outside line and allow a seam allowance around it when using panals- sometimes they are (out of whack) and need to be straightened--by pulling/stretching diagonally to straighten them up- and pressing.
if i can not get the lines to straighten up on a panal i will cut inside the lines and square up the center without the lines showing that it (was) crooked
the fabrics are PANALS--there is nothing cheating about using a panal--its the same as using any other printed cotton fabric-just a design element.