Start to squat, that'll improve your bench. It's been well documented that heavy leg training will cause an increase in your natural test levels which will cause gains throughout the body.
Next..... stop training chest twice a week. Your overtraining it. Cut it back to once a week. I agree that some smaller muscle groups (tri's, bi's, calves,etc....) heal faster and can be trained more than once a week, but larger one's (chest, back, legs, etc...) once a week no more.
NEXT, if your doing 215 for 15 reps, try 235 for 12, 255 for 10, etc... if your able to easilly bang off 15 reps it's time for more weight. Simple as that.
Lastly.... listen to your doctor. He didn't spend thousands of dollars and go to school for like 15 years to not know what he's talking about. If he says your arm isn't fully healed, it's not. Your going to damage it more, and damage some nerves while your at it. My buddy doesn't have full mobility of his arm or full control of his hand from a breakage... do you really want to set your training back multiple years over a few short weeks?