The snakes eye will clear up right before the shed. What I do to get my humidity up to "shed weight" is once they get pink belly and blue eyes I'll lay a wet towel on top of the cage and I just keep wetting it till I get a good shed. If you try this, make sure you wring the towel out good. You don't want it raining in the tank.
And yes, Pet stores will sell you things that you don't need, They are there to make money, plus most people who work at them don't know everything about all reptiles. The salesperson may keep bearded dragons, which need UV light, but they may not be aware that BP's are nocturnal and don't need it. I trust this forum over a pet store because there is alot of BP specific experience here. And yes, I too have that drawer full of useless junk that the pet store initially swindled me into. So you are not alone. As was mentioned above, the best investment you can make is a thermostat and Under Tank Heater. I used a rheostat until I got the money for the t-stats, and they do work. You will find that once you get the heat and humidity right, everything else is pretty easy...
Rob