Hello Alice,
Thank you for your reply. That link didn't seem to work, but I eventually managed to find the page and downloaded KSDK 1.3.0. Now I have a project with a GUI that looks familiar, with the KSDK 1.3.0 peripheral drivers replacing the Kinetis legacy high-level components.
For anyone interested...
As of today, it seems KSDK 2.2 can not be used with PE. MCUXpresso isn't finished, and it only generates v2.2 SDK's, and KEx is just rebranded MCUXpresso. So, in order to use the peripheral configuration GUI, KSDK 1.3 must be installed and used in conjunction with KDS v3, even for bare metal projects. The KSDK 1.3.0 Eclipse Update also has to be installed. Then you have to create a new "Kinetis SDK 1.x Project," point to the KSDK install, and check the PE box. The peripheral drivers are under "KDSK 1.3.0" instead of "Kineits," but the component inspector windows are pretty much the same.
Software I downloaded and apparently don't need: Kinetis Expert Config Tools, MCUXpresso (IDE, SDK 2.1 and 2.2 configurations), KSDK Project Generator...
IMO not an obvious path from non-SDK KDS and PE... maybe this is documented somewhere, but I never found it.