Fires are already forbidden in the Great Gulf Wilderness. Of course, one still sees evidence of them.
Interestingly enough, in looking that up in the 2010 Backcountry Camping Rules, it appears that the 200' off-trail camping regulation is only listed as applying to the Dry River, Pemi, and Great Gulf Wilderness areas. In particular, you explicitly only have to be 200' off-trail for the first mile south of the Wild River Trail from the campground.
PS - the regulations against geocaching and letterboxing are included in this pamphlet.
Interestingly enough, in looking that up in the 2010 Backcountry Camping Rules, it appears that the 200' off-trail camping regulation is only listed as applying to the Dry River, Pemi, and Great Gulf Wilderness areas. In particular, you explicitly only have to be 200' off-trail for the first mile south of the Wild River Trail from the campground.
PS - the regulations against geocaching and letterboxing are included in this pamphlet.