You're appealing to authority here, or it's just your opinion? You always have an off switch.
Indeed, but there are instances in entertainment history where niche and not widely known individuals/ shows are received into the mainstream and it's seen as brilliance. The same goes in reverse too. Kings new clothes syndrome.
If Heather makes 'a show' her own and builds her audience then power to her. The entertainment industry is shallow, fickle, and full of 'could haves'. Once in a while a beacon shines out; I'd suggest Steve Warner is one of those lights; Heather could well be another.
Not at all. Seriously, did you not learn about such things in school? An appeal to authority is when someone says an idea is correct based merely on the authority of the person making the claim -- that because the President says it's a good idea, it must be so, for instance. It's the same fallacy as the personal attack that's so popular around here, except instead of refuting the idea because of who said it, it's about accepting the idea simply because of who said it.
An appeal to authority would be like saying Heather's great simply because Art Bell thinks so, regardless of her actual ability.
People's individual opinions about whether or not she is good, and their supporting points within the limit of assessment -- the quality of her voice, her ability to converse, the depth of her questions and responses, and so forth -- are simply their assessment. They don't rely on Art's or anyone else's opinion to make the claim.