Well your getting there. When using a tub you want a few holes in the side for venting and not a screen hole in the top. That is the issue with the glass enclosure you have. Heat collects moisture and rises to the top so if your vent is on top....out goes the moisture. But for a royal that is a big step in the right dirrection. Now personaly I would get a bigger tub and use an old soldering iron to melt 5-10 holes in each side of the tub about 2-3" below the top lip. If you want to see the snake better cut a big rectangular hole in the side and cover it with plexi like a window.
Also adding a moist substrate like cypress or reptibark will help your tub out a lot. Hope it works for you and kudos for putting pride away and taking the advise given. Now get another snake for your glass enclosure