Another piece — "select a bunch of pre-connected nodes, right-click them into a macro and all publishing and cable connections are done for you" — doesn't have a public feature request, but we're already working on it and are planning to release it in Vuo 1.3.
One reason that you might see banding is if your monitor supports fewer colors. If that's the problem, adding some noise (as in the attached composition) should help.
To check if you really are getting an 8bpc image, you can open it in an image editing application and check the number of unique colors. For example, in Photoshop, go to Image > Mode > Indexed Color. The maximum unique colors you could see with 8bpc is 256. If you see slightly fewer than that (like 246), it's fine. If you see a lot fewer, there's a problem.
I've been using the app called TRNIO to generate a 3d model (.ply) and texture and I'm having trouble assigning the texture to it. Actually I can assign the texture to it but it's not acting as it should here