You don't have to care if we loose a day at the top spot, we won't get the 1# on Hot 100 this week anyway. Also, this week 400,000 people will download the song, despite Capitol has removed the song from itunes.
I'm sure next week we will get that 1#
Roar is generally pretty low and suits her voice more than Wide Awake or Firework. She's probably been in vocal training for weeks knowing she'd be at the VMAs. She'll be fine.
It will definitely get back that #1 spot on iTunes US but her chances at getting those WW #1's again are really slim now considering that the song has yet to climb a long way again, this time without the hype of the "official release." Also, it's not like other countries care about the VMAs so saying that the VMA performance will do wonders again for the song WW is completely dubious. What we have now left is the music video for the WW market.