1) Reader Voz Is Goshien (comment on this post) confirms that the 1% for Visa Business Edge will post as a statement credit.
2) Staples caps your purchases with a Staples Gift Card at 5 gift cards, so you can only do about $500 at a time.
3) I got a call from Staples that they weren't happy with my order. They didn't want me to buy Visa Gift Cards with Staples Gift Cards. I had the choice of canceling the order or putting it entirely on my credit card. The phone call was only triggered when I tried to buy 5 at a time. I was able to successfully buy one at a time.