1. 128....MB, haha but seriously that's more than enough. 2.Yes, it does. The original firmware. 3.use this awesome site to build your payloads http://www.ducktoolkit.com/Home.jsp 4.There is a whole bunch of tutorials all over Youtube, I've done a couple on how you can flash it to any firmware under kali, and 10 (fixed) prank payloads. you can take a look here. https://www.youtube.com/channel/UCFQ8rlDKp4PtpHOyZYHPMmQ/videos.