what causes that taste?

Hotdog?

Rubbing alcohol?

What is the hop flavor like?

"Hot Dog" flavor comes from autolysis. It's when the yeast cells die, and rupture. First it's sort of "meaty" or like hot dogs. In severe cases, it gets a definite fecal smell.

"Rubbing alcohol" is fusel alcohols. They are higher order alcohols, which can also be called "hot" or "solventy". (Different molecule than ethanol). Generally that comes from a too-high fermentation temperature, and/or stressed yeast.

Hop flavor? Well, hops provide bitterness, but they also have other flavors. Some are a bit fruity or floral, while others have some earthiness. Think of hops as the "seasoning" in beer. Just like some foods have oregano, some beers have noble hops. Some foods have tarragon, some beers have English hops. It's part of the flavor profile of each beer, although some beers have no real hops aroma or flavor that is discernible.

Good info, how do light and temp flucs affect the beer?

Light will skunk the beer. If you're not sure what that means buy a Heineken

Temperature fluctuations freak out the yeast, and they tend to do unfortunate things like generate weird flavors (fruits, solvents, rubbery), or just poop out and stop fermenting.