Ok so let me start off by saying that im not an expert and if any of my information is incorrect feel free to point it out.

From how you described your setup, it sounds like you're going to have a tough time maintaining a proper humidity. The overhead lights really burn off the water vapor in the tank and dry 'er out. The lights you are using to heat with really arent the preferred method of heating, try getting ahold of some undertank heat sources like flexwatt. BP's prefer belly heat and dont require a strict light cycle to be healthy.
Two hides are a must, so the snake can choose between being warm or cool, not warm/cool or secure. The grapevine twig isnt neccessary, and if you find yourself short on space take it out to make room for another hide.
You can pick up a cheap thermometer/humidity thing at walmart for $8, and it will do a much more accurate job of checking the levels. Also the "dirt-like flooring" is probably not your best bet for substrate, try getting some aspen or just plain old newspaper.