Clean the bottom bracket shell threads really well (w/ rubbing alcohol), do the same w/ the bottom bracket cups, use blue loctite and make sure you torque the cups enough when you install them ("really ****ing tight" is a rough figure). Then if you ever need to pull the cups you can just use regular tools and won't have to bust out a torch (as you would with red loctite, etc.). Provided the threads are cleaned properly and torqued enough you shouldn't even need the loctite, but it won't hurt in this case and it'll hopefully give you some confidence back in your setup (your bike isn't ****ed).

Seriously, riders were/are using Italian threaded bottom brackets for decades. It might not be the ideal set but your bottom bracket isn't just magically going to eject itself if you install everything properly. Just don't half-ass the job and you'll be fine.

And as for powdercoating a messed up frame and then trying to return it, I wouldn't be surprised if IRO has already dealt with that situation. There's always some *******/idiot out there trying to pull off a new scam.