Lots of speculation here, and some wrong.
I just installed 1" spacers on my 19" brushed aluminum rims (pictures in the PANHARD BAR INSTALLATION thread). When I hang a weighted string from the fenders, the tires are just barely touching the string. So, if the Brembos have a more aggressive offset, that WILL result in the tires sticking out more than the fenders if you use 1" spacers. If you like that, then good.
As for safety, only the front studs needed shortened. Further, only the "lead in" part of the stud needed shortened a little. There were no threads taken off, so the safety aspect from that perspective is a non-issue.
You can argue two things from safety perspectives: The spacer lug bolts could loosen, or the lugs themselves could fail. IMO, both are non-issues. If you tighten the spacer lugs to the specified torque, they present no more risk of loosening than the original wheel studs (plus, I am using high strength threadlock on them just in case). And, the spacer lugs are supposed to be of the same or higher strength than the OEM lugs. I cannot confirm that, obviously, but choose not to be that paranoid.