i think that its very important that if someone is interested in psychedelics, and using psychedelics at events like psy-parties, raves, festivals, etc. it is vastly helpful to have someone more experienced help introduce them to the scene. sometimes these things can be such a culture-shock (especially with a headful of psychedelics), that the new trippers might get the wrong impression.
also make no mistakes--music especially psychedelic music, is designed from the ground up to affect your mind. this can be anything from simply strange, trippy sounds to elements put into the music to make you think, reprogramming your own mind. psy is all about timestretched movie samples and other things to grok at while you are all tripped out. a distinction you need to make is that it ISNT just the people throwing the party or surrounding you that want to share this music, its the producers, the musicians the people who recorded it in the first place. the DJs just play these records because they feel the will fit the vibe of the party. if it is darker, then so be it. many fans and DJs and producers into darker psy that i know, feel that the darker vibe helps you work through a possibly darker trip then sort of exorcise the darkness from you--or something like that, in sort of a yin and yang kind of way--i dont know.
i am not that into psy but you are hardly alone with your idea of feeling conspired against at a psychedelic event. read the electric kool-aid acid test and you will find that owsley (the first large scale underground LSD chemist) had a very similar experience the first time he went to an acid test featuring the grateful dead. he promptly split and drove immediately into a telephone pole he was so freaked. there can be great psychic power at work when you have a mass acid experience with the right music, but this shit is incredibly unwieldy. it kind of does it wants, making a conspiratorial theory like yours a little hard to realize, if at all possible.
http://books.google.com/books?id=M4zx5dxTMqwC&pg=PA249&lpg=PA249&dq=owsley+freak+out+trips+festival&source=bl&ots=dF9RXpbaJs&sig=3FB-Oh5SFgHww8irDVvctq1f5qg&hl=en&sa=X&ei=tIHDUf2TK9iu4AOeoYBI&ved=0CCoQ6AEwAA#v=onepage&q=owsley%20freak%20out%20trips%20festival&f=false