1) The technomancers have no real reason to hide anything from their ALASTAIR allies, and moreover they are always thrilled to talk about how brilliant they are, so they'll gladly explain the rift machines' details to anyone who will listen. It's all a bunch of complex math and quantum mechanics combined with magic, though, and they seem incapable of dumbing it down, so actually understanding it is a different matter altogether.

As for their creation, it's purely in order to help ALASTAIR; the cats themselves do not use them. They also don't know much about the state of the Timeline itself, and say that those questions are better suited to ALASTAIR veterans.

2) The catnip is just mundane, regular catnip; we already answered this question here!