I recommend asking the manufacturer.
Yes, this should be compatible with a folding stock adapter.
Yes, this should be compatible
Doublestar does not state the specific castle nut that is used with the DoubleStar ARFX AR-15 Skeleton Buttstock. However, the only Doublestar castle nut we have available can be found at the link below. If this isn't the castle nut you are looking please email us at techsales@opticsplanet.com for more information.
https://www.opticsplanet.com/doublestar-car-castle-nut.html
Yes, this will work well.
No, the DoubleStar ARFX AR-15 Skeleton Buttstock is designed to work with rifle length buffer tube. So it will not work on an AR pistol buffer tube.
This DoubleStar ARFX AR-15 Skeleton Buttstock will not work on a Ruger PC Charger.
The DoubleStar ARFX AR-15 Skeleton Buttstock does not include the buffer tube with the kit. You can find the correct buffer tube in the link below.
https://www.opticsplanet.com/doublestar-buffer-tube-for-a2-buttstock.html
This is meant for an AR-15 and will not fit any AK platforms without some sort of adapter that will accept an AR buffer tube. The KS47 is set up to accept standard AR buffer tubes, so you should be able to use this in place of your current buffer tube.
Yes this should be compatible.