Many of the big breeders raise leos on nothing but mealworms. It won't hurt anything, but a variety of feeders is definately the best way to go. And as stated in the previous post, babies/juvies should be fed every day. Even as adults most leos will eat every other day, some more, some a little less.
As far as crickets giving leos pinworms. Many people think this is a common occurrance, Marcia McGuiness with Golden Gate Geckos (a very reputable breeder) explained on a different forum, in detail, that this is not really true. Here is part of her post from that forum, it was dated 3/6/2006:
I would like to try to clarify some confusing information about geckos contracting pinworms from feeder insects vs. being infected themselves since routine fecal test results cannot always tell the difference between pinworms that are actually infecting the gecko and the ones that show up as a result of the crickets/mealworms being infected with them. Pinworms cannot infect geckos and feeders at the same time.
Pinworms are sometimes hard to avoid. They are so common that children can become infected pinworms from playing in the dirt. I believe that just about every gecko breeder and keeper has had to deal with these parasites at some time or another, and fortunately they are easy to treat. However, since routine fecal test results cannot always tell the difference between pinworms that are actually infecting the gecko and the ones that show up as a result of the crickets/mealworms being infected with them, here is something to keep in mind...
When a gecko is infected with pinworms, they will show up as tiny oocysts (eggs) and larvae under a microscope, and are not visible to the naked eye. Now, if a gecko ate a cricket that was infected with pinworms, the larvae and worms would be easily observed, sometimes even with the naked eye in the feces. These pinworms pose no health risk to the gecko.
I thought this would be very good information to pass along, I sure found it very interesting 
Shelley
-----
www.StoplightCityLeopardGeckos.com