1. Yes, but Guides themselves must be nonhuman at least to start

2 and 3. There is an age range among guides, they were created for different reasons. The earliest Guides showed up about 15 years ago and until recently their mission has been observing and learning about humans. That said there is no guarantee that they were completely successful at this learning, most older Guides likely think they know a lot about humans but have a lot of weird misconceptions.

4. Guides do not currently age physically and are typically in the age group of a young, healthy adult animal