confirmed

I'm gonna reference this issue for now... it's always on the backburner, but just not something we've had a chance to work through. An alternative would be to look into the multi page checkout module that was being developed, though I'm not sure even that will work without JS.

I understand the "dont partially fix it" argument, but this i think should be considered a show stopper?

As a fix i don't think (caveat: i've not looked into it enough yet) that it should be to hard - if there is no shipping set, you set the error as you do currently but if there is a delivery location is set, then pre-populate the shipping div with the correct options/html?

I don't think there's any way to fix it as is in 5.x. Any fix would involve a reworking of the checkout form... If we allow that submit and then change the shipping values and redisplay the form, we don't have a good way to account for empty required fields (and other forms of validation) that haven't been filled in yet. But even just selecting a payment method uses AJAX for something like the Credit Card payment method.