You can download some layouts other people have already made from here. If you installed LFS Z28 with the installer package you can simply choose to Open the layout rather than Download it. The layout will be automatically copied to the relevant folder on your PC and when you access the Autocross menu for the corresponding track you'll be able to open it. If you didn't install LFS with the installer you should download the layout (lyt) file, right click on it and select "Open With..." find your LFS.exe file and remember to tick the "Always open with this application" box. To manually place layout files put them in <LFS Folder>/data/lyt.
This is an old myth. But I wouldn't hold my breath if I were you. Personnally I don't think this is ever gonna happen. And if it is, probably not before a long while
They only mentioned that the plan is to make all AutoX objects unified - all objects available for all tracks. Nothing huge, but if you guys want ramps on other tracks, it seems to be coming for you.