Using a phone holder as a display is a cleaver trick I came up with, it's useful to display a CD on it's own, if you only have one or two CD'S and/or very limited space on a merch table it can be a great space saver to have CD's displayed like that and have them stored in a box under/behind the table or in a bag under/behind the table, they can also surprisingly cheap to buy, including even cheaper plastic ones that come in multi packs.
I done merch for Duran Duran in LA and Las Vegas. It's a good idea to make up a sandwich board with the prices and a pic of the band or album. T shirts are always a good earner.
I’d say that traditional mailing lists are kind of a thing of the past now. I guess it depends on your audience demographics but if you’re playing to millennials and younger then things like instagram replace email mailing lists. Just put your socials handles up on a sign.