If you want to look for a place that won't be noticed, to do a test sanding, consider the part of the door that will be hidden behind the round part of the hinge. Personally I think sanding will be fine, but I would perhaps use a finer grit than for solid wood, and i would move the sanding block so it was moving from the painted side to the planed side rather than going the other way (then pick the block up off the door and move it back to take another swipe), which could rag the laminate/paint or scratch the painted finish if you slip7
Is the door to be mounted on a kitchen/bathroom/external or other place that generates lots of moisture?