Those sure do appear to be cankers to me. The limbs that appear to have canker may eventually succumb to it, and those can be pruned off. Canker on tree trunks may eventually cause tree mortality, but sometimes that's not always the case. One of the problems with large cankers is the interior
wood tissue like the cambium layer and even wood beneath that become exposed to other infectious wood rotting organisms and pests. Healthy vigorous trees can often heal themselves, which may appear to be what is happening in the appltree1_2 pic. The bark develops this round kinda curling appearance as it tries to cover and grow over the wound. Some of the cankers look absolutely awful, like the appletree1_4 pic. That's a big, gnarly canker right amidst a multiple branch union. The branch in appletree1_3 is a candidate to be cut off like 12 inches behind the canker or all the way back at the trunk (it's hard to tell how far down the branch that one is or the size of the branch). If those were my trees, I would do appropriate pruning where applicable, and I would make an attempt at treating some of the minor cankers with a spray of Effective Microbes and raw neem oil, and repeat those applications all year long, for a few years, and then only time will tell if the tree bark slowly grows over the wounds. Btw, cankers are caused by bacterial and fungal infections, usually at a previous wound site (but not always). It's usually the girdling effect of cankers that cause death to the living tissue past the site of the canker.