Okay, did some more troubleshooting and got it working!! Basically I did EVERYTHING in Ch 3.3 of Jay's guide.
Here is what I did:
1) At the end of Ch 3.3 there is a sections called "Reseting IOS 8 Network Configuration :-". I did this on ALL my iOS devices (iPad on 8.3, iPad on 7.1, iPhone on 8.3) first, then went to the top of the chapter.
2) I also tried to logout of iCloud, but I could not. It is because I could not logout of keychain. I googled the issue and followed the advice to uncheck stuff in safari to allow you to uncheck keychain, but it didn't work even after a reboot. But I logged out of everything else inside of iCloud except for keychain.
3) After that, I deleted ALL of the hidden files/folders per Ch 3.3, to include the ones in "Resetting the Security Service settings :-". (I had to reboot into single user mode '-x' in order to empty the trashcan, then reboot a 2nd time to get back in regular mode).
4) Re-checked everything in iCloud that I wanted.
5) Double clicked iMessage in Yosemite, logged in with my apple account and password, viola, worked!
edit: I also hit 27.5 hours since my call to apple with the code, so maybe it could have been a time thing, too.