If you cut the arrows to 30in, drop the weight tubes, and use 175 grain heads the tuning should be pretty identical. You'll just gain 5% foc. You'll gain 30 grains from cutting down the shaft and adding point weight but lose a few from the weight tubes. So you should end up similar in arrow weight just with more foc. The weight tubes can pop out on hard hits. Adding point weight is the way to go. Your current set-up will work but I'd drop the weight tubes, cut the shaft, and get a heavier head. The heavier the head the thicker it can be so it'll stand up to hard hits better. If the arrow ends up lighter than 500 grains I'd go up in shaft spine, cut to 30, and add point weight.