1) As TJ says, access cannot be denied under the Land Reform Act. What may happen is that trails get trashed by logging and aren’t repaired, but that is not the same as forbidding access.
2) If new trails are constructed, there cannot be a charge for their use, as this also contravenes the LRA (which the naughty boys at Golspie are doing). Drumlanrig (for example) is exempt from this as it was charging for trail/estate use prior the LRA coming into force.
You/the petition is also assuming that because the forests will be let out to a commercial company that there will be a wholesale logging and restriction on access to these areas. How these companies work with local communities and the communities of outdoor users who enjoy these spaces is up to each individual lease holder and you can’t assume that they’re all going to be evil money grabbing bastards. As mentioned already, FCS is hardly a bastion of good management/practice/PR so perhaps some competition will up their game.
I think people need to be a little more open minded about this, unless you can give me firm evidence that these proposals will doom jobs and recreation as a result.