Nothing wrong with learning the variations since (unless you are competing) they maybe a bit more practical. Yes, if you do not have the technique proper, you run teh risk of getting injured…then again I have seen people get seriously injured benching, squating, deadlifting, mili pressing, curling, shrugging…shit come to think of it, I almost (must emphasize almost since every minute another knucklehead does something stupid) seen an injury doing any exercise on any kind of equipment when using bad form. So if you want a kickass workout with a twist, throw in some of the variations. I think Dan John has workouts that gradually integrate some of the lifts on his site.
Oh, just thought I’d slip in a correction, I am in fact using not the full lifts, but power cleans and power snatches, that is, I don’t drop to a full squat on the lifts, but rather use the form described in “My thats a nice snatch you have” and a similar article about the power-clean by CW, don’t remember the name of that one (not as catchy I suppose…)
I have missed lifts a couple of times without problems, I have a proper bar and bumper plates.