I know very little about editing pdfs, so I can't answer from that end.
For grins, I looked at my system.
I'm using Acrobat 4-exchange, could not find a reader directory in program files\adobe.
I installed the 4.0 version of the reader, then went into file association step above and changed association from .exe file in acrobat subdirectory to .exe file in reader subdirectory.
When I click on a pdf on my desktop, it opens with reader vs full program. At this point have no idea if those steps created other messes I'll have to clean up.
You could probably do the same which would force workstations with exchange to open any pdf in reader (unless they opened exchange prior to opening a pdf). Don't know if that will/would solve your problem.