I had the transfer failed message last night too, but I think I just shut down the app and logged back into PSN and it worked.
Chrome, so the ability to use the background image to trace is only on the flat Eifel then? That does suck, but I'd bet it's the elevation variations that they figured would not allow you to create your track the way you want anyways... a flat(ter) surface allows that much more easily. Still, we should have the freedom to try.
I found a few more annoying limitations:
Kart tracks, or even using karts on any of the tracks is a very precarious ordeal.
Eifel (both) - curbing is not actual raised, slanted curbing, but a strip placed where it should be, leaving a large pertruding shelf where the road sits. All cars feel this as a sharp tug on your wheel when you hit curbing (not the usual impact of the curb). But Karts, forget about it. You are left with only one option... never hit a curb or a track edge, or you're dead.
Death Valley - Does not have any curbing at all. That is actually better for karts, because the above situation at the "Eifels" is not present. However, the immediacy of the invisible wall creates major problems for any minor bumps against it. Some have raised concern about wall-riding, but that is not likely to occur given how sticky those invisible walls are. It would almost never yeild you positive results as a would be cheater.
Sierra (what's it called?) - has much better curbing that is actually raised and slanted, much like what we have in AC and pCARS. This stuff does not adversely affect karts attempting to innocently gliding over them... up to a point. The curbing pieces here are much longer than those that are placed on the Eifels. When two pieces come together, there is a taper on each end. If you place two pieces in succession, the two connecting tapered pieces create a small hole in the curbing. If your kart hits one of those, and it will, you are still very much deceased.
Some good stuff, but also some bad stuff, unfortunately...
