I agree with flipper336 - GET RID OF THEM SHOES or give them away to someone who they will fit.
Bathe your feet in warm salty water to get some relief and elevate your legs as much as you can to rest your feet to speed up healing.
With regard to the blue calf, it may be that this may be a just bruise. Sometimes we get little veins that can rupture and you will see the blueness. If you press on the area and notice that the blueness comes it is likely that it is from that. Get this checked out by your doctor so that he can give you the correct diagnosis, usually nothing is done about it.
If you do experience pain in the calf, get that checked out to rule out deep vein thrombosis. A Doppler blood test would indicate if there are any problems with regard to that. As you haven't mentioned pain in the calf, it is not likely to be that.
As you did get broken skin and did walk barefoot, you may have picked up bugs. If you notice any changes for the worse, get a rash and itchiness, start to feel unwell get checked out by the doctor as they could be signs of a bacterial infection.
All of the swelling would be a result of wearing the shoes that were to small, from what it sounds like all day long. The pain is also from wearing them and walking home barefoot.
I am not sure why your calf would turn blue, but I can tell you that it would not be from an infection. Personally I would give it a couple of days just to see what your calf does. If it turns blue again I would go see a doctor. Also get rid of the shoes. :-)