I think I have the power issue figured out and a few other problems that crept in.
Heat: If the motor runs at 5v, it does get hot. I added a 6Amp dropping diode in series with the 5V so now it runs on 4.3V which is about equivalent to a charged 1S battery.
I also discovered some of the motors I ordered were the same size physically but didnt' have any power at 5v. Those needed 7.4v (2S battery size) so if you order those motors, you can use this supply and just dial it to run all the electronics with 7.4Vdc. Use Vin on the arduino and it will step that down to 5V.
It's not UL rated :( so don't use this one, but find something similar....
Here are the updated parts I used on the latest Coast Guard Rescue ship:
Hobbypower Rc 10a Brushed ESC Motor Speed Controller 1/16 18 24 Car Boat Tank W/o Brake(Pack of 2 Pcs)
SHNITPWR 5V 8A 40W Power Supply Adapter AC/DC Converter 100V~240V AC to DC 5 Volts 8 Amps Transformer with 5.5x2.5mm DC Tip for WS2812B WS2813 LED Pixel Strip TV Box USB HUB Raspberry Pi Arduino
ELEGOO for Arduino Nano V3.0, Nano Board CH340/ATmega328P Without USB Cable, Compatible with Arduino Nano V3.0 (Nano x 3 Without Cable)
diymore 5pcs Nano Expansion Prototype Shield I/O Extension Board Module for Arduino Nano V3.0
I will post a schematic soon...