Good post. I was been lucky enough to get a job at a reptile store that has been in business for about 20 years, and I understand completely where you are coming from. We carry high and low end animals, but probably 90% of our business is still new pet owners, feeders, and dry goods.
I believe the best way to educate our customers by example; for instance, every display on the floor is the actual appropriate set-up for that animal. That care to detail goes a very long way. You are right in that it's near impossible to become an expert on everything you sell though. I had to learn husbandry for everything from bearded dragons to monitors to all kinds of snakes as fast as possible to do my job responsibly. The employees of the store need to be aware of the weight of their actions and advice with customers. Rather than making something up that "sounds right", they need to find someone who knows, or look up the correct answer before giving that information to customers. Needless to say, my first weeks working at the Reptile Center had a lot of ...."Sorry, I don't know. Ask that guy over there"
Not all LPS are bad! But make sure you support the ones that are good! Those LPS customers are the ones that go on to become YOUR customers.