[quote}My understanding is that the FC has crown imunity, the land is effectively in the hands of the state. That means they cannot be held liable like any other land owner for claims. [/quote]
I don't think this is the case. As I understand it they don't need to hold insurance like regular landowners / local authorities to indenmnify in the case of accidents. Mostly that's down to the state having a really big "purse", not that they're exempt from responsibility.
This is one of the reasons we can actually MTB on FC land. Can you imagine trying to sort out risk assessements and public liability insurance for Cwm Carn if you were a landowner? It would make it impossible to get anything off the ground. This is why it is so important to keep our forests out of private hands. If we loose the FC we'll loose legal MTB.
The public forest estate is mamaged by FC, not owned by them. It is owned by the state. They risk assess the trails anyway, irrespective of whether they have to hold a specific insurance. Look at OGB37 etc.
The FC exploit crown imunity, MTB is an important diversification for them, but they have to do as much as they can to keep the local emergency services and hospitals happy. Unfortunately you can't protect idiots against themselves. I think thats why they are making the changes.
Again, not my understanding. I'm not sure claims would be brought under the HSAW Act anyway. H&S is absolutely fine TBH, we still kill far too many people in construction, agriculture (including forestry) for me ever to think it's a system and structure that should be done away with. The problem is more often (IMO) people's (often site managers / policy makers) poor abilities in the assessment and handling of risks.
Case law in climbing has established that there is a concept of informed consent i.e. if you partake in an activity that has inherent risk knowingly then you accept it (came about through climbers on crags on local authority land IIRC).
Waivers etc are meaningless AFAIK, you cannot "trump" responsibilities under the law like that. If a facilitiy is provided it needs to be fit for purpose. How you define it and what that fitness is all depends.