I don't know if you need admin access, but Workbench certainly can't run in a locked down environment. By default it caches a lot of run time information in the install directory. For instance, I have Workbench installed in
C:\Program Files\Adobe\LiveCycle80\Workbench ES.
Under there is another directory called Workbench and under that is a directory called workspace i.e.
C:\Program Files\Adobe\LiveCycle80\Workbench ES\Workbench\workspace
That directory contains a .metadata directory which itself contains the Eclipse log (useful for whenever Workbench reports one of it's useless "see error log" error messages) plus some other stuff. When you are logged in, you'll see a directory named for the Workbench connection which, I think, contains cached information from the server.
It's obvious that the workspace directory is in entirely the wrong place - I don't know what the Adobe engineers were thinking when they chose that location. There may be a config option to put it somewhere else, but I haven't found it yet.
I was going to suggest giving users full access to just that workspace directory rather than making them full admins, but it occurs to me that, even then, only one person on the Citrix server will be able to use it at a time.