I completely agree with your assessment of the problems. I totally destroyed that marine board plastic trying to get one of the bolts out. I was lucky and was able to remove the Bandit without sawing. I did drop one of those threaded inserts behind the grill and it did take a while to remove it.
I ended up getting the Slipstream license plate bracket from Thatgrin.com, although the price has gone up a lot since I purchased. The brackets attach to the vertical sections of the grill and is very easy to remove and install. I'm happy with it so far.