User Manual AmazonBasics C18-RK18W01B Induction Cooktop

The smallest size that I've used is a 4 inch cast iron skillet

It is a bit complicated, as you have to press PLAY/PAUSE after it has been pluged, then power button, and then set temperature or "heat level", I found myself pressing everything after a while not using it.

Hard to tell but we used our biggest pot to cook. It is portable and you can plug it anywhere

No. There is plenty of room for a 12" pan without the buttons melting, however. I heat a 20 quart stock pot on it with no issues. The surface does not get not where the pan is not in direct contact. It is induction and not direct radiation. Even then, the heat is minimal where its in direct contact.

As long as you have access to electricity to plug into yiu can use it anywhere.

No, this will not work with aluminum cookware. The physics of induction will only produce heat in a ferrous metal. If a magnet won't stick to it, it won't heat.