i always find these discussion interesting, mainly because there seems to always be a split between "intellectual" techno and techno for the unwashed masses. why there has to be a split is beyond me. people like to polarize things i guess.
as far as constraints go, i personally find those constraints interesting. i love really far out experimental stuff too, but as far as djing goes, i do like working within a framework.
i remember the first time i ever heard miles davis "kind of blue". in the liner notes, he talks about how the playing in jazz had gotten so far out that melody was being lost. so on kind of blue, the players were constrained by a certain scale, but could improvise inside of that framework. what happened was an incredible album based on certain constraints, but definitely an amazing result.
for me, the interesting thing about djing is that, yes, i DO wanna see people go crazy on a dancefloor. the real challenge is to mess around inside their heads at the same time they are shaking their asses. if i wanna listen to really obscure, esoteric music, i do it at home sitting with a book. but if there is a giant soundsystem in front of me, i wanna rock the **** out. doesn't mean i can't let it move my brain as well, but i do tend to drift if it's too abstract in those circumstances.
i know this is somewhat rambling, and perhaps i can put together a more cogent explanation when i haven't been up for hours moving all my shit into a storage space. ;)