Does this bolt directly to the factory catalytic converter?

Yes. This system connects at the factory cat outlet and uses factory mounting points for the rear axle area, so you're looking at a straightforward bolt-down install with standard hand tools.

Will I need new gaskets or O-rings when installing?

That depends on the condition of your current connections. If the factory gasket at the cat outlet is in good shape, reuse it. If it's cracked or crushed, pick up a replacement gasket from any Honda parts supplier — they're cheap and worth the peace of mind on a fresh seal.

Can I drive this in wet conditions without worrying about rust?

Stainless steel is corrosion-resistant, so salt spray and moisture won't eat through the tubing. The tip may develop surface patina over time depending on climate, but the structural integrity stays intact.