Hey Chris/Andrew,
I'm really sorry this isn't working for you and everyone else. There is definitely something wrong on Google's end. I contacted them on Friday and informed them of the issue our merchants have been experiencing, so hopefully it will be resolved soon.
Unfortunately the error we display in the app is basically just a copy of what Google sends us when the app does a "dry run" of publishing your products. So until they fix it on their end, new merchants cannot publish anything. I've confirmed that existing merchants can change their target market in the app, add a new shipping method in merchant center for that country, and not get this error. So it seems to be an issue only with new merchant center accounts.
I'll be sure to post any reply I get from Google on this forum asap.
Cheers,
Shawn