Hi Josh,

The misshapen leaves on your peach tree are caused by a disease called peach leaf curl.  That disease is pretty bad this year in the midwest, although from your photos, I'd say that your tree doesn't look too bad.  Tree will recover from this no problem.

Cankers like that on the trunk -- the only thing you can do in this situation is to prune this out.  This canker will eventually girdle and kill the limb anyway.  If you can burn the pruned limb, that is the best way to dispose of it and prevent pathogen inoculum from spreading from the limb back into your healthy trees.

George Sundin