This is the best part of our culture and I won't hear otherwise.

Any fermented, malted starch drink is technically a beer. Chicha which is made entirely on corn is an ancient native Americas drink; many South-East Asian countries make rice lagers or ales; authentic ginger beer ferments raw sugars and ginger; gluten-free beers are often made with rice, sorghum, quinoa or other non-wheat and non-barley grains. There’s a plethora of different beers out there made with very different ingredients that all share the same brewing process.

So, yes, as long as you were able to malt the sweet potato to induce sugars that you then ferment using yeast without distillation, you’re producing beer.

No no, has to have sugar. Some sugary liquid.

I sometimes use sweet potato for beer in a similar way as I do pumpkin. Just clean it up, shove it in the oven until it caramelizes a bit, mash it with a fork or whatever is at hand and add it to the mash - I usually use 1-2 kg (~2-4 lbs) for a 20L (5 gal?) batch. And from then on it's brewing as usual. Gives a nice colour to the beer though I can't say I've noticed any flavour.

Read about being able to mash them on their own, but I've yet to try that, not sure how I would go about it.