The hood vents may be a potential issue where water might be able to penetrate, but I'm not sure how much water would be required to actually cause hydrolock. From what I read.. it would need to be a substantial amount. I don't know much of how it all works out though driving through extreme wet conditions.. I'm a bit more conservative with intake mods. But, I fully support your idea of making the engine able to breath better.There is zero chance of sucking in water. The cone filters are fed from the same holes that feed the stock intake and water (not drops) would have to pour in before it would be a problem. If water got that high, the stock system would suck it in like a straw vs an open cone filter. If the cone filters were exposed directly to the rain, then yes, that would not be good.
Also a few drops of water down the intake would actually help with IAT's. There are guys that spray water down the intake to help cool the charge (But wet filters are bad for flow).
My friends Charger SRT hydrolocked after driving it on a rainy day only a day after he had one of those low mounted cold intakes installed.