Hi Eric,
What was the "annoying" part of keeping them that your vet referred to. Just seems like an odd term to use for the care of these little guys. 
You will find mixed experience on this forum. Some have been quite successful and others not. I had a 1:20 CB trio in 2003 and they all died within 2 weeks of one another. They were 4 months old when I got them from the Kammer's and they lived another 5. We do not know what happened. May have been supplementation which can be tricky - as with any species. They are tiny animals and even if something is diagnosed they are hard to treat due to size. When Bart (the last to go - named after Bart Simpson b/c he looked like him! lol!) died I had an offer from an out of state vet to do a necropsy and see if he could find anything that would help future brevi keepers. On the way to my vet (to get him into Formulin (sp?) my alternator in my car went and my neighbor was not willing to drive me (45 min each way) - UGH! It was really too bad I could not get him there. May not have gotten any answers, but maybe we would have.
I know of others who seemed to "just lose them" whereas roo, and others here, are quite successful. Be sure to see his articles on chamnews. I do plan on getting more soon as they are curious little creatuers.
1. active? not especially, but funny. Makeda, my larger female was so tolerant as Bart would often climb over her if she was in his way. I'll have to dig up some old pics of them.
2. can't comment from expericne but there are stories of people not even knowing she had laid eggs and suddenly found babies in the tank. I know that R. brevi are egg bearers, not sure about other species.
3. a waterfall is not recommended for any setup due to the chance of bacterial and fungal buildup. In such a humid environment it would be worse. Also, to constantly have to take out and clean you'd be a pain in the butt b/c of the substarte, plants, etc. I would nix the waterfall idea - and yes, they probably could drown if they did not have a rock, branch, etc. to grab onto.
hope that helps and I am sure others will chime in with their experiences.
lele
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