Nearly all vegetable and fruit juices will ferment. Most directly, though some need added sugar, or tweaks to the pH with bicarbonate or vinegar or similar. Some of the odder ones I've heard of are cabbage and tomato.

Easily, though the remaining flavors once the sugar is converted to alcohol aren't pleasant; it would have to be a fairly sweet wine.

My grandparents made dandelion wine and potato wine. My dad tried making it a few years back for a trip down memory lane, and they really were not the sort of thing that you would want to drink much of- given how cheap everything is nowadays, it's more for the novelty.