I spend a huge amount of time in my work editing other people's artwork and the number one issue is embedded images that have been pasted in (instead of file-> place).

I have to jump through lots of hoops to get files to process correctly.

I'm not sure how it would work, but an option to have embedded files restricted by default, with a preference to allow it (with a warning dialog) would go a huge way to instilling the right working practice in new users.

And save me a huge amount of time.