Looks fine to me. Looks like you tried to center it on the riser. Can't see from the photo, but the ideal position would be for the pressure point of the rest to be directly above the deepest part of the grip. This may or may not be on the center of the riser. Not a big deal, just something to remember for next time.
If you used the adhesive that came on the rest, it shouldn't be hard to remove when you need to replace it. Just rip the old one off and clean off any remaining stuff on the riser with Goof Off or the equivalent. If the adhesive that came on the rest is dried out or doesn't stick very well, you can supplement with Barge, which is also easy enough to clean off later.
You shouldn't need to elevate the rest any more than the strip that came with it. Some people use a broken off toothpick if nothing comes with the rest.