You NEED a tstat. The uth can easily burn your snake. Unplug the uth until you get a tstat. I love my Herpstats. Buy the best tstat you can afford. Buying a cheap one will mean it will need replacing when it breaks which will add up to the price of a good you in a few broken units. http://www.spyderrobotics.com/home/products.html

You can use bulbs or a che as long as they are giving you the correct temp. Both can also cause a hotspot directly under them that is to hot. The easiest way to check surface temps are with a IR temp gun. They are cheap on Amazon.

The pet store gauges can very very inaccurate. I would upgrade them when you can.

To help your sheds here are some tips.
1. Cover the screen to leaving a window for the light and heat to pass through. Use foil or foil tape. This will help hold some humidity and heat. Some people use a damp towel but I don't like to because it will rust the screen top.

2. Mist the tank daily, maybe a couple times a day if its really dry. At the first signs of a coming shed (red/pink belly, dull colors, foggy eyes) start to mist more often.

3. Create a humid hide. This can be as easy as keeping damp moss in the hides. I do this. Every few days I dampen the moss during non shed and allow it to dry out. During a shed I keep it damp.