Just pointing out the details. All those little things add up to the over-all appearance. It is in your best interest to inform the client of what will look better. Just because you are 15 doesn't mean you can let your clients push you around. If the HO wants the project to look like a homeowner did it then let them do it. It's your reputation that you are trying to create. Sink the bricks deeper and at least get them to ground level so that when someone mows they can put the wheel of the mower on them and minimize trimming. I'd still also set them in mortar so they don't ever move.