Looks like the PTO was definitely the issue. I finally had time to pull it off last night and you can see in the pic what I was left of it. I think I might have shed a few ball bearings!
Ha!
I did start the engine just fine following removal.
Pulling it off was a breeze - one hit with the impact wrench on the center bolt and then it slid right off. It took me longer to disconnect the wiring harness than anything else. I am not sure why they wound that thing around under the engine mount and made it tough to deal with. I'll do something better than that when it goes back in (like maybe a wire tie to keep it where it needs to be). BTW, I didn't end up removing the hood - just the grill (well...technically it doesn't really stay in but it was not there). It was very easy to access with just a socket and an extension.
Any recommendations on the best replacement PTO? Also, will the replacement PTO come with everything set (I believe there is a gap that gets set by the 3 bolts surrounding it).