re: Tree disease help

Looked at some pics, and apparently it is a sweet gum tree. I'm just trying to figure out what is causing my new trees die. Didn't know that was normal on the bark. On my new trees, one about 3 feet tall has none of that, whereas a slightly shorter one is covered with it already. Glad to hear the bark thing is normal, but would whatever causes the spotting on the leaves kill a small tree?