Great photos! The right hand passage has been deteriorating a lot over the last few years, it's looking increasingly crumbly. There's quite a nice mine directly opposite on the south side of the valley about fifty metres up the scree slope on White Rake that never makes it onto Stoney Middleton surveys, worth a look next time you're there.
Generally agree, but there's no access restrictions to any of the mines or caves of Stony Middleton apart from Eyam Dale House Cave, which is in someone's garden. It's the most commonly used training area for young cavers in the Peaks, and the car park right near the mine is the haunt of many climbers as well, BMC regulate use of the quarries.