I don't have an Adobe installation log, and it's not hidden either. I tried installing Illustrator CS4 again, and I noticed that the install fails while ~80% through an "initializing" step. So, it fails before it even starts to generate an install log! I re-downloaded it and had the same error.
I did notice that I have some errors in the Adobe CC Cleaner Tool when I was removing Illustrator CS4. If you look at my first post, I couldn't use it, or uninstall it, so I simply used the Cleaner Tool to remove it. There are some errors in the Cleaner Tool log, such as this one:
2014-11-02 15:11:19.319 Adobe Creative Cloud Cleaner Tool[1573:8801317] The following session will be removed: bf2f18d647916c8449e4a221e4609a2
2014-11-02 15:11:19.324 Adobe Creative Cloud Cleaner Tool[1573:8801317] Deleting the payload: {78F4C3FA-BE2D-4392-A98A-68A3498E3E94} from the table ribs_payload and other associated tables for payloads
2014-11-02 15:11:19.324 Adobe Creative Cloud Cleaner Tool[1573:8801317] ERROR: Cannot delete the payload due to constraint: {78F4C3FA-BE2D-4392-A98A-68A3498E3E94}
To make things worse, Adobe Support Advisor has been discontinued, which could interpret errors contained in Adobe logs.
I contacted Adobe support via chat, and they simply told me that Illustrator CS4 was not supported for Yosemite, and did not offer any further help or information...
Any other ideas? Or am I simply stuck??
Thanks for all of your advice!
it looks like ai cs4 and yosemite are incompatible, http://roaringapps.com/apps?index=a (according to others that have tried).