Two points about free-roaming
Two points to make here:
1) Would not do it with Beardies. I used to live in a place with three south facing windows (actually SE, S and SW); bear in mind I am in the northern hemisphere. Had a linoleum floor, so I placed two specimen trees (Murraya paniculata and Dracaena marginata) in the SE and Sw window on each side of the bed. Allowed my pair of green water dragons, Aussie water dragon (that's him, btw), Tiliqua, White's tree frog (what you call a green tree frog; we have our own "green tree frog," Hyla cinerea) and a big Polypedates dennysii to all free roam. Placed big saucers of water by each tree.
Well --it worked out great! The frogs would sit on their plants during the day, and trade places with the arboreal lizards at night. Even the frogs quickly learned where to soak when necessary.
How-ev-ah, the male WD did start to exhibit behavior "issues." Pete Weis, a former respected breeder in Florida, USA explained to me: When you get a baby lizard, cage it while it is growing. Teach it to associate you with food, and pet it in its enclosure more than picking it up--that is how you hasten trust-formation. Allow the animal to free roam when to young, and you essentially have a lizard living in your yard--(s)he will still have a "flight distance." Taz (my avatar) lived in a 20L for the first 1 1/2 years, so he was/is tamer.
Also, space is no guarantee of peace--the lizards would sometimes face off and fight. It seems that, like fish, more space means something worth fighting over! This was solved with pet barriers, which they grudgingly learned to accept.
As for house-breaking, this is easy. We know that many lizards will eliminate in water. So how about placing some wet newspaper around the water basin? Then gradually shift to dry newspaper. It actually works rather quickly. One rub: Sometimes I do fall asleep when reading--and no, they do not read the date on the newspaper first....
2) But--I would not do this with any animal inclined to hide once in a while; the risk is too great. Arboreal animals sleep off the ground where I can see them--makes life rather easy. I did get worried about the skink occasionally trying to sleep in back of the refrigerator, not a good idea. So, no, I would not do it with an animal that may try to sleep under/behind the bookcase, behind the frig, in the hamper, in boots, etc. (Hell, even ferrets and cats can get into predicaments, no?)
