That viv is perfectly fine, you just need to find a way to draw air from the bottom out of the top. Did Dd design this specifically for a chameleon? If so they should be able to make that adjustment free of charge. The whole top needs pulled off to allow uvb lamp and a couple of fans. The fans are there to create negative pressure within the enclosure, forcing it to draw fresh air up through the bottom. Exoterra terrariums have a vent on the front that makes this a breeze. Maintaining humidity is a bit difficult without increasing the frequency of misting. Which if over compensated will give you many many many bacterial and fungal problems
Is the top sheet of glass sanded or is it as easy to slice yourself on that pane as it looks in the photo?