Hi Pasta, i cant answer all of your questions but........the hiss of air from the forks I had on my bike, it turned out too be air escaping from the fork gators. Theres tiny holes in the back of them to release air as they compress. It could be that one of them isnt seated properly so doesnt hiss. Easy test pull them up from the bottom so theyre loose one at a time. If the noise stops, problem solved.

Good.luck with the rest.

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