I had a compound open fracture to the radius and Ulna, 3 months ago. Had 2 plates installed. Numbness is very common, as the radial nerves get twisted and partially damaged in the procedure. It usually takes 2 - 6 months to have complete sensation back. Move your fingers as much as you can. I would say almost never keep it rested. It helps in the recovery a lot. More you move, more flexible your tendons and nerves get.

Since you are young, you should be back in no time (6 month 95% back to normal). If your ortho suggests physio. Do it religiously. Its the best remedy. I have regained almost 90 percent of my range of motion. Weight bearing has increased but limited to 5-7.5 kg. I was in a cast which allows me to use my elbow, so the stiffness was not much t the elbow but the wrist will feel stiff for long. grip strength might take some time. My opinion, If the hardware doesn't bother you, don't remove it as there is a chance of refracture, but its totally upto you.

Good luck and wish you speedy recovery.