ZK, actually I don't believe a toxic dose for vitamin C has ever been found. There is some evidance, though not enough to warrant much concern at this time, that a very high intake of vitamin E (800-1000 iu's+) may have a negative effect on androgen receptors. Still, take one or two 400 iu's caps a day, and you should be fine. I've used the 1000 iu caps in the past and they didn't seem to impede my gains, so this effect, if it exists,is probably minimal.
As far as the zinc, I see little benefit to taking in large amounts. It could in fact block the absorbsion of other essential minerals. What is in a quality diet and your multi-vitamin is probably more than enough. The idea of zinc increasing testosteron levels is hype. Its a marketing ploy for overpriced, worthless suppliments.