My rosys seem to do best when the humidity is between 30 and 50 percent. I've never kept them in higher humidty though, so I can't say for sure what would happen.

Lights and CHEs dry out an enclosure. I've had to steer clear of them because the humidity is low where I live, but they might be just what you need. You can also take the water bowl out entirely and only offer water a few times a month. They don't drink much when humidity is high and getting it down to acceptable levels is more important than keeping a water bowl in the enclosure.