There are a few options for pluging the holes if you move your plate somewhere else, though you will still have 3 dots there to deal with. There are chrome semi flush plugs that will clip into the hole and look reasonable. I used these to cover the upper support mounts for my stock pipes when I put on a Thunderheader (uses the standard lower mounting holes).
I saw this cool LED turn signal kit which replaces the side mounted rear turn signals with an LED license plate mounted bracket which places the turn signals as an LED arrow > on either side of a laydown license plate frame. They are independent so they could be mounted closer together if you removed the plate. You may need to make or find a cover (or HD skull medalion might do) to cover the mounting kit. Wish I took a picture of this.