What repair required the dealer to mess with that? You can do the heads without disassembling it. FYI, I had a similar problem last month except my stud had fallen completely out.

 

I repair those all the time. Use a stud remover and some heat but the trick is to start the engine let it get hot to get the stuff out and then hand torque it. Anything else just snaps it. Only trick is if you are doing a head job then break the secondary air pipes when its cold then heat it up or else the inserts will loosen instead of airpipe.
and yes we do improvise its just some techs can't see past being parts guys and be diagnosticians. Sell the part first then worry about repair latter.

 

my choice for quick fix is your option #3. You could drill it out--install a heli-coil--reinstall a stud & nut , but thats more work & $ for the same result. Yup, drill straight through and install a good bolt.