the important thing with philosophy, I think, is to keep it in the realm of the possible.
a good example of this is the typical "free will/determinism" line of argument.
this can be argued indefinitely, but how much can this REALLY affect your life?
the important thing to gain in that situation is to realize what is personally true. you are free to believe that you are free, and also free to believe you're shackled to fate. but the mere belief in one or the other doesn't exactly change your situation.
same thing with morality, you can debate the goodness or evil of a certain action for weeks, yet you ultimately will "do as thou wilt"...
its basically coming to terms with things as they are, "it is what it is" etc.
but that's also relevant to the books you're considering,
say you read "how to win friends..." the info is there, you got the info, now what happens? its significance is entirely up to its relevance to you and its applicability to your own life.
in general, it is my belief that if someone has a "notion" that something MAY help, its worthwhile to explore, as at worse, it is no help, and you have wasted minimal time. you can read 3 chapters of a 20 chapter book and decide its not for you.
that being said, I find it interesting that the jobs you do apply for so consistently have this pattern...you would think different places have differing situations, not universal replicas of the same "posh normie" dilemma