That looks about right, after doing some quick math. I got 8.64 A (@ 60ma per LED) not counting what the Pi uses.
I have one of these 5V 10A switching power supplies, 5V 10A switching power supply : ID 658 : $29.95 : Adafruit Industries, Unique & fun DIY electronics and kits
And a couple of the 4A versions. No complaints, they worked just fine for me. I cut the barrel jack plug off and soldered on my own Micro USB cables. The barrel jack (jacks) that I found were not rated for 10A, or even 4A. Keep that in mind.
My 5V 10 A supply is wired up so it can run up to 4 Pi’s at once.
I wouldn’t think so no, not even close. The actual spec is or was I believe 1A max.
I replaced the barrel jack on my 10A supply with this. T Connector Male-Female Pair – Pimoroni
I just soldered on my wires and heat shirked them. For cables to the Pi(s) I used these. Mote Module Cables – Pimoroni
I cut them in half and only wire up the power leads to the T connector. I didn’t have to use the T connector but it gives me options to swap cables latter on without having to redo things.