Rich Text Editor messes pages in certain cases. {latex} and {flowchart} macros are good examples. For example:

{flowchart}
Yksi -> Kaksi -> Kolme -> Yksi;
{flowchart}

Is converted to this just by clicking Rich Text Editor tab:

{flowchart}
Yksi \-> Kaksi \-> Kolme \-> Yksi;
{flowchart}

which, of course, spoils the diagram and that, in turn, makes the Rich Text Editor next to unusable (in our case, anyway).

Fortunately, there is a simple solution to this. I suggest that you improve Rich Text Editor by adding some filtering capabilities there so that certain macros will be bypassed by Rich Text Editor. This filter could be a simple list where a Confluence admin can add all the macros to be bypassed. Or maybe the list should contain macros that can be handled by the Rich Text Editor. But to put it simply, there should be a way to manage what Rich Text Editor is allowed to "edit".