I think the cited usage is something of a malapropism / mixed metaphor. It should be one of either...
switching, [as] quick as a flash [to something else]
switching, [as] smooth as silk [to something else]
Note that both the above expressions occur many times in Google Books (which I've linked to). But there are virtually no instances of ...
It is almost certainly a mistake, as the expression "quick as silk" not only makes no sense (silk has no speed) but it cannot be found anywhere else.
This is not strictly a "malapropism", as it is unlikely one would hear "flash" and think it was "silk". A malapropism is when someone gets an idiom wrong by substituting a similar sounding word, eg "he danced ...
It may not be a common metaphor, but it makes perfect sense if you know what shot silk is - basically, it is silk fabric made with different colored warp and weft threads, so that every slight movement of the cloth changes the patterns of color you see.
Frank made a rapid shift from making a reference to a dirty joke about a princess, to retelling the story ...
Actually, the meaning of "He may not come today" is ambiguous, at least when written. You would have to use context to understand what is meant.
When spoken, there would normally be a different intonation, depending on what the speaker intends to say. If there is no particular emphasis, or if the emphasis is slightly on "may" the meaning is, "The ...
is its own is not a phrase.
its own clearly definable concept is a noun phrase, the complement of is.
Its own here means "standing on its own, not requiring reference to something else" rather than "belonging to itself".
I found another version of the lyrics, which has 'All good devils set me free', which makes slightly more sense: bad devils torment me in hell, but good devils set me free (which means they're not really devils).
Where did you get these lyrics? Online versions of song lyrics are sometimes of variable quality.
In short, "whose" is the couple, and "trust" is a noun.
Rephrase the sentence.
Add commas (for clarity):
The thought of the unwary couple, whose trust he has carefully cultivated, excites his blood-lust to a fever pitch, and he can barely hold back, these last seconds, before climbing out of the coffin, to seek his prey.
Remember that "...
Fit to print simply means suitable or appropriate for printing. News might not be fit to print because it is pointlessly scurrilous, or unsubstantiated, or not of interest to anyone, or puerile. It implies being selective as to what is published, but selective in a very principled way.
The character of Kevin Roberts is not a representation of a real person, just a 'typical' annoying person from the 1980s (we get this from the oversized-cellphone, fashion and the music he dances to).
The joke of the entire sketch is that the FBI shooting range is training cadets to quickly distinguish "good guys" from "bad guys", but you have annoying ...