I was partially able to solve this, but I don't know why this is so much more complicated than Cinema 4D's sweep nurb. In C4D, a sweep allows spine control (for varying thickness) easily, creates UV's automatically, and doesn't have to do strange things like start with an open circle of 359 degrees and exchanging U and V coordinates to avoid ugly seams. If one adds a polycap, it creates ugly renders like above. I have to select the end loop and create groups to have it behave properly. Here is a fix with notes to show the issues and an updated file. Please, SideFx, make this easier - if you want to market Houdini to modelers.
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