Murray, the crosshair explanation is at the page Mousethief linked to specifically, here. It's happened to me when I've taken photos. One also has to ask what crosshairs being obscured would prove. Did someone go paint a crosshair on the background of the photo? Did someone draw them on the photos and then paste images on top of them? If they're so good at faking photos, you'd think they'd notice that big old plus sign.

As to radiation, the dosage is determined by the intensity of the radiation and the exposure time. They reduced the exposure time and so reduced the dosage. Victims of Hiroshima and Nagasaki suffered from alpha radiation poisoning. Alpha radiation is particulate - fallout/radioactive dust. If you inhale it or ingest it, it's deadly. Watch "The Day After" and look at all the dust on everything.

The radiation the astonauts were exposed to was gamma radiation, in the form of rays. It's the same type of radiation they use for cancer treatment, and we get from x-rays and the sun. I don't have any facts to hand, but I'd be willing to bet cancer patients undergoing radiotherapy receive a higher dosage of gamma radiation than the astronauts did.