Okay, I give you IYSA. It was controversial but I mean half of the world don't understand what that song is about. I didn't know about its controversial until I joined ATRL. Songs like Womanizer, Circus, Out From Under, Trouble,.., are very safe. They are very catchy.
Its not about safe or not safe only either. Circus was way more ambitious than Blackout in most aspects. Blackout is cohesive but very one dimensional and quite honestly, Circus has aged much better.
And I agree, Britney's dancing obliterates that 2007 vma stand in, her swag and IDAGF attitude made that performance the iconic moment it HAD to be, had she slayed the choreo it wouldve been basic.