What I did is delete the entire project and start over, and I ran into no issues. As far as the "missing" files I was quoting the lazarus documentation on the matter. I was using the latest download from sourceforge. The links in the readme to the treeview-unstable are outdated, they are now located in treeview-new.
I also wanted to note that using the latest repository version of all necessary libraries results in a working CentrED compile. I may have been getting the ClientHeight issues from using the wrong/out of data library versions.
I also wanted to note that using the latest repository version of all necessary libraries results in a working CentrED compile. I may have been getting the ClientHeight issues from using the wrong/out of data library versions.