Venus is a novel by Ben Bova, part of his Grand Tour series.
This book contains examples of:
AB Positive: Lars is able to supply a treatment for Van's condition. Makes sense, considering he's Van's biological father.
Bizarre Alien Biology: Semi-averted; one character comments that the microbes in the Venusian atmosphere are just as susceptible to death by vacuum as are humans. Played straight by the organism on the surface; there's only one of them, and it has fingers in the entire planet.
Hoist by His Own Petard: Van's allowance is cut off in order to fund the prize for finding his brother (and given his status as The Unfavorite it's actually kind of surprising that Martin gave him one in the first place). Van ends up winning said prize, and Martin is forced to pay it.
Stone Wall: Lars' ship, the Lucifer. His "overdesign" helps ensure the survival of the craft in the atmosphere of Venus. There's some concern as to whether or not it'll survive the trip back up due to the microbes nobody predicted would be there, but it manages.
The Unfavorite: Van, whom Martin hates. It doesn't help that his mother died in childbirth. On top of that, Lars Fuchs, Martin's arch-nemesis, is actually Van's father.
Used Future: If the art on the hardcover edition is anything to go by. The ship on the cover almost looks like it was kitbashed.