Braz, I highly doubt you're going to be able to boot Win7 from USB yet. The only option I could give you is to download pebuilder, and find a tutorial online about creating a boot file for the OS through that program. You also have to download a USB boot file creator to make sure your flash drive is in fact bootable. Burning the .iso file of Win7 onto a DVD is your best option and worked flawlessly for me. Booting from a flash drive isn't quite reliable enough to use it yet in my opinion. I couldn't even get a flash drive to boot WinXP, and that was supposed to be easy.
And yes the contents of that flash drive are correct. BUT, since you have it all on your flash drive you'll need to enter the command
oscdimg.exe -u2 -b"E:\boot\etfsboot.com" -h "E:\" C:\WIN7.ISO
That is if you DON'T have all those files in the expandedSetup folder.
If you do have the files in the expandedSetup folder on your flash drive you'll enter
oscdimg.exe -u2 -b"E:\expandedSetup\boot\etfsboot.com" -h "E:\expandedSetup" C:\WIN7.ISO
That'll put the .iso file in your c: drive after it's done creating it.