Problem solved. I've been beating on our Symantec support guy and he sent a copy of the WF to engineering, and they opened the project just fine. Support sent me this snippet from WF support:
One item of note, if ever prompted to update/refresh/replace any libraries when opening a project, always uncheck everything before clicking ‘Next’. This may be where the problem was encountered or it could be that the ASDK generator was ran incorrectly at some point. All of the types mentioned in this screenshot are ASDK Generator types.
Opening the ASDK Generator project and going through the wizard it runs may resolve the issue. Alternatively, a copy of the out-of-box of this library may help too.
....so, that got me thinking that if it opened fine on theirs, I could try to open the project on my other dev box. I exported it with the default option "Exclude Core Libraries" checked, then imported to dev2 box. It opened fine there. Then I exported the project and unchecked Exclude Core Libraries. I ported that project back to dev1 and when prompted that it would over write core libraries, I checked the boxes to over write them. POOF, all is good and right in the world... at least for my workflows.
So I fixed it by doing what engineering said NOT to do... sort of (but it sounds funnier when I say it that way). I just corrected the core libraries which is what they also suggested.
Just wanted to pass this one along and hope this helps someone else too.