I have my bearded dragon tanks on similar timers. It's the exact same concept as with fish. I've actually run a fish tank and reptile enclosure on the same timer.
With the UV, the lizards that need it need UVB specifically, 280nm - 315nm I think, and there are bulbs designed specifically for this. Without it, those species will develop what is call metabolic bone disease (MBD), which results in deformities and various other problems, from a lack of vitamin d production and calcium utilization. I think all animals benefit from some UV, I am redesigning some cages to incorporate a better UV light source. It goes along with the natural day/night light cycle. Promoting normal behavior, etc... I have been looking into building some LED light strips, the types people are using for fish, as there are some UV LEDs available now. Most of the ones I've seen are around 400nm, so they won't do for the animals that need uvb, but might be good for some others just to get a more "natural" light. I was going to ask around here is any of the fish guys had any websites or companies they would recommend.
There are multiple ways to control humidity. That is actually on the list of articles. Reducing air flow, using a moist substrate, adjusting where and what type of heating, forgers/misters/spraying systems. I use a simple digital outdoor humidity monitor, with a probe on a wire. And no, there seems to be no way to get an exact measurement. I don't think it is as important to have a constant humidity, I let most of the enclosures "cycle", wet them down in the morning and let them dry a bit through the day. It greatly reduces the chance of any mold, which can be quite bad. It depends on the species and the necessary environment. I actually go mostly by "feel" at this point. I don't actually measure humidity much at all, though for someone with little experience it may be helpful.
