She's got questions...

I must preface my post by confessing that the last and only time I took economics was in 12th grade, and so my apology in advance if my questions make me sound like simpleton (though maybe I am!).

1. The textbook defines economics, as "the science that studies how the economy allocates scarce resources, with alternative uses, between unlimited competing wants" (p.3). To me the key components in this definition seem to include (1) scarcity in supply and (2) insatiable demand. However, if we are trying to understand the economics of the news industry in today's media environment, it seems reasonable to assume that the current dynamic includes (1) too much supply [in terms of news information] and (2) too little demand [for news in the face of entertainment in this high choice environment (Prior, 2007). I wonder, then, if this helps explain, in addition to other factors such as their mistrust in Christensen's disruptive technology thesis, etc., the news industry's inability to figure out a viable economic model for their operations?  In other words, can economics apply to the state of the news industry today given it entails phenomena that seemingly contradict the basic assumptions of economics?

2. Does the law of demand only apply to things with ceiling effects of some sort (e.g., that the supply would eventually run out)? I understand that supply and demand are closely linked with strong negative correlation, and the definition of economics seems to suggest as much (e.g., scarce supply), but then what happens if there is unlimited supply of something -- what would the slope of the curve look like if we extend the X-axis on the hypothetical graph of supply and demand that we are drawing, since it is unlikely that at limitless supply demand will cease to exist?

3. In terms of substitution effect (p.18) -- I wonder if substitutes only apply to "comparable goods?" And if so, what would be the definition of "comparable?" For example, if I wanted to buy a car and I am thinking about getting a Honda, Toyota or Hyundai would be "substitutes" in a classical sense because they are different brands of comparable nature (e.g., same price range, etc.), but I may even consider getting a sports bike (e.g., Aprilia RS125) and it would in theory still count as a "substitute" because it serves similar purpose (e.g., transportation) despite vast differences in terms of price, safety concerns, etc. 

Nonetheless, what happens when we move from more concrete things such as cars and motorcycles to things that are more discursive in nature, such as media content? Particularly -- does entertainment count as "substitutes" for news? (This goes back to Markus Prior's point that in high choice environment "people forgo news in favor of entertainment") And if so, doesn't this in a way suggest that "time" is actually the IV rather than content ? (e.g., entertainment counts as substitute for news because it is simply a "choice of genre" given time availability, and thus the issue here is more so time displacement than anything else). I buy the argument that digital media are "inferior good" compared to their traditional counterparts, but what about "media content" if we leave the medium alone for a while and focus on different genres instead? How "good" is content?