I’ve had a Koxx wheel, Mad4one wheel, KH frame, Koxx frame, and Quax frame and they all fit on everything else so I don’t think you’ll have a problem there. Nimbus probably will as well, I can’t tell you for sure but I think I’ve seen a bunch of people mixing up KH/Nimbus/Koxx.
For the K1 hub it depends if it’s the old version or the new one. In the past they used this messed up ISIS sizing so if that’s the case you’ll only be able to use old K1 cranks on it (Koxx one street cranks are the best out of these IMO). But if it’s the new style you can use any ISIS cranks (KH, new Koxx, M4O, ect). To find out you should probably just call the store you ordered it from, they should be able to tell you.
Koxx One Alien Backflip frames do not fit on Nimbus hubs unless you modify them. The bearing holders won’t fit past the spokes without being filed down. In this thread you can see how Saskatchewanian filed down his bearing holders to make the frame fit on a Nimbus hub.