Anything with water can absorb CO2 and be carbonated, but you don't have to do anything but hook up a CO2 tank to the keg holding said water-based item. Root beer can be done in the brewery, steeping the various roots and herbs, but you'll spend a fortune getting said same aforementioned roots and herbs, while the Zatarain's extract is foolproof. I **do** heat up water to dissolve sugars for root beer; that can be done in the brewery. And yes, sugarS. Various corn, table, light brown, dark brown sugars can be layered to make different root beers.
In the end, it all goes in a keg, hooked up the CO2, and then the kids love pulling a glass from the tap.
A tap with a auto-return spring.
A strong auto-return spring.
Over a mat.
Preferably outside.