the bracket in box 1 is used for a ATX PSU, so if you want that option you can use that one instead of the already installed sfx bracketJust opened mine. Amazing quality. What is the bracket in box 1 for? Also, those fan grills that come in box 1 are for use on the radiator fans I assume?
EDIT: Also, can front IO cables be used alongside 2 bottom fans?
and from my experience with the fans under my GPU, it is a tight fit becasue the cables are rather thiccc, so you need bend them or shift the fans as far ass possible to the back of the case for more room. i personally dont use front I/O that much and switched to the cleaner only powerbutton option, and with less cables its way easier to install such fans. but it will fit, you just need to squeeze a little
EDIT: yeah those grills are for when your fanblades are turned to the inside, to protect them from all the cables.