Welcome! You really hit the nail on the head on this topic by doing your homework ahead of time. It sounds like you're a lot like me - you can make a plan for everything except for animal's own individual behavior.
Without any other information, there would be blind responses that will tell you a 20 gallon glass aquarium is far too big and exposed for a hatchling. You gave a lot of other information though - thank you! You can certainly make up for things by cluttering it up to make it feel more homely like you're thinking about doing. When I started out, I used display enclosures as well (an Animal Plastics T8 divided in half). The PVC helped a bit with the exposure part, but you can cover the sides of a glass tank to replicate that. For clutter, I used crumpled up newspaper and as they grew, the amount of newspaper necessary shrank. There will likely be humidity issues to deal with in a glass tank, but there are ways around those as well. As long as you can make a plan to meet the animal's needs successfully, and have plans B, C, D, E, F, etc ready when the animal tells you your plan sucks, there isn't a right or a wrong way to go about things.
Rule #1 - Be Educated
Rule #2 - Be Flexible
Rule #3 - Have Fun
*rules are in no particular order
Again, welcome to the forum. You're right - there are a TON of knowledgeable people here. I hope you enjoy your stay!
Best regards,
Eric
PS - If you haven't seen them already, here are a couple very informative threads I think you'll enjoy:
- Ball Python (Python regius) Caresheet - http://ball-pythons.net/forums/showt...s%29-Caresheet
- How to Setup a Glass Tank (20 long) With Pictures! - http://ball-pythons.net/forums/showt...With-Pictures!