We have a weeping birch that has suffered ice damage, losing its top a few years ago and then a big main branch this winter. The bark has developed a dark red "growth" that it has not had prior to now. Some preliminary web searching says it might be a serious problem with no solution. Should we be concerned? The tree is next to the city sidewalk and street parking and about 35' tall.
Linn County Oregon
Difficult to tell a lot from the images but will give you some direction. The yellowish redish growth may simply be an lichen of some sort. Would need a very closer look to be sure. Here is more info on that aspect:
The first image does some a little sapsucker damage but it does not seem to be a major problem:
I mention that because you may have an insect problem called bronze birch borer which could result in the symptoms you have described.
You may also have wood decay in the center of the trunk that came in after the ice injury. There is not much you can do for that.