In Yona 4:8 why does Yona build a succa that allows more sun than shade?
The Posuk does not say that there was more sun than shade. On the contrary the Posuk says "Vayeshev Tacteho Bzel" which translates into "He sat under it in the shade.
The following Posuk says that a Kikoyon was shade upon him, and the Radak explains that this happened 40 days later when the Sukka dried out and therefore it was not providing shade anymore.
He built a hut to protect himself from the elements while watching, expecting at least something bad to happen to Nineveh. Nothing to do with the holiday.