My calf catches my derailleur when I pedal
If you're bike is properly assembled, and fitted, then your problems rest not in the bike, but likely in your foot position and your pedal stroke. 

First, I would have your bike fit assessed to determine if you're riding the right sized bike, and that the saddle is properly adjusted. If the bike is properly fitted, then you need to change the position of your foot on your pedal and how you execute your powerstroke. 

One simple solution may be to switch to clipless pedals if you're not already using them. This will somewhat force you to place your feet on the pedals properly. Other than that what you need is physical training to train your legs to execute a proper stroke. Unless you simply have very large calves, it's likely that you have an improper balance of strength in the vastus muscles of your quad. You need to consciously train your leg not to come within proximity of your derailleur until your weaker muscles get stronger and you develop some muscle memory. 

If the reality is that you simply have large calves, then your only solution may be to remove the front derailleur and upgrade your bike to a 1x11 speed. until then, you can try wearing compression sleeves or socks to protect your skin.