Which one is benefited more by entry hazards (and Rapid Spin) in general: offense or stall?
Well this sets up a bit of an unfair dichotomy IMO, both of them appreciate support.
As a Stall player, I can say that hazards are pivotal, no good stall team doesn't run rocks, and almost all run spikes or a spinner, rarely you can get away without a spiker or a spinner. Offensive teams like hazards to KO certain Pokemon much better, and rapid spinning is nice you they aren't weak to hazard themselves, but they don't need them, plent of offensive teams don't run spikes or a spinner.
So, stall teams need hazards, and arguably rapid spin, to work, while offensive teams don't, to answer your question.