I have lots of micro - usb chargers around the house, car ect. Will i still be able to use these to charge the new S7? What is needed to fast charge the new S7 phone?
You need a quickcharger, which comes with the phone, to quick charge the phone, but it can charge with pretty much every micro USB charger out there at whatever speed those chargers are capable of reaching.
The chargers you already have will work but they won't fast charge unless they support the feature. A compatible phone and charger are required to fast charge.