Update: I solved the problem. Found most of my answer thanks to this post: http://social.msdn.microsoft.com/Forums/en-US/sharepointinfopath/thread/c04ef25e-d0f1-4d6d-bb39-f103ffe1fee5
Solution: find all references to offending (missing) data object in the .xsn "package" files that are created when you design your InfoPath form template. Namely look in manifest.xsf and any other files. Rename the old object name with the new object name or remove it altogether whichever is applicable in your case.
At first I didn't know where to find the files in the xsn package. To find them I copied the xsn file and renamed it by appending ".cab" to the name. This essentially creates a zip file or cab package that allows you to view all the contents inside the xsn file. (I didn't know this until I read this article: http://www.xml.com/pub/a/2003/10/29/infopath.html). Once the files were extracted I then opened them all (e.g. *.xml, .*xsl, *.xsd) in Visual Studio and searched for the name of missing object in entire solution. I found 2 files where it was referenced 3 times. One of the files to change was manifest.xsf and then the other was a section control of my form.
After I made these changes I republished the form to my SharePoint form library and renamed the template too. Everything works great now. (It only took me 4 hours to fix the problem). Note to self: avoid changing data connections attached to complicated rules after the fact. Once requirements are established with user, don't allow scope creep. :)
Thank goodness for google!