My snake is about to shed. His eyes went white on Saturday and cleared today. Since Saturday he was sat all stretched out on the forks of the branch on the cold side of the cage.
Not uncommon. Mine usually go in the hide on the cool side... however they spend the majority of their time on the cool side it seems.
He ate a very small fuzzy (next size up from pinkie mouse) on Saturday morning and let the other lay.
just be glad he ate. out of my 5 snakes, 1 wont eat all when it gets close to shed, two will just eat less, and the rest will eat just like usual. It's dependant on your snake. No need to worry so far...
I have decided he is sneezing.
From my understanding, this is the possible start of a respiratory infection. Taking him to the vet is the right thing to do in this case.
He also does another really weird thing. He opens his mouth like EXTREMELY wide every now and then.
This is commonly done after eating to realign the jaw.
When he sneezes, nothing comes out.
oh come on im sure air comes out
... I haven't ever had a snake do this, but I don't think stuff normally does... but someone please correct me if im wrong here.
I did take him off the branch to see what was up and he sure drank a lot of water from his dish and sucked the water drops off the outside of his dish.
Does he have easy access to his water dish? Maybe he was just thirsty 
Anyone have any idea how serious this is?
I would have him checked out by the vet for the sneezing.. and it wont hurt to mention the other stuff. If nothing more, it will let the vet know you are definately a concerned individual.
He refuses to stay off the branch and the cold side. Can this be good for him? Has staying on the cold side for days on end made him sick?
What are your hot/cold side temps? You may just have the temps too hot for him. For his size, i'd keep the warm side somewhere around 82 or so. He's growing, therefore more surface area to absorb heat, so he doesn't need the temps quite as high. However, my licorice stick black rat always stays on the cool hide, and my black rat always says on the branches. Being an everglades rat snake it will stay somewhat arboreal... they love trees. Give him/her some more climbing sticks, and you'll see a lot more activity!
Actually I just looked at your website... it seems that the branch gets higher on the cool side. I've noticed my snakes liking to get as far up as possible. You may want to try and put another branch at the same height for the other side as well.
I doubt that made him sick however, I'd just keep the vet appointment. You caught it early, and it should be completely treatable.
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-Chris
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