Almost fixed (hints for anybody else who runs into this)
The sites on the old account are now usable. I'm still having some issues with some of the paths to javascript files not being completely translated by virtualhostmonster (most work, but ace-editor for editing the dexterity XML is not working).
I did two things that both seemed to be necessary:
- I deleted all the rewrite rules to sites that didn't work making sure to completely clear the line of code where each was. I then retyped the rewrite rules (actually I copied a working one and edited it). I kept a copy of the deleted code. They look identical, but maybe there was a non-printing character.
- I added a blank line immediately below the last rewrite rule in the chain.
This makes things much better, but not perfect. However, it does look like the problem is primarily associated with how Apache 2.4 reads the virtualhost .conf file.