According to Mesa Tactical, the components are made from high grade mil-spec hard anodized aircraft aluminum.
Any recoil pad that fits a standard telescoping AR stock will fit this one.
No- the adapter itself will interfere with the beavertail/tang that rises above the horizontal portion of the grip.
Mesa Tactical does not claim that the kit will fit a Remington 879 DM, but it will fit the 870 DM.
You will first need to ensure that you are acting in accordance with any relevant NFA specifications, but this kit will physically fit the 870 Tac-14.
Yes, this will fit the Remington 870 DM.
It does have QD attachment points. It appears the image on the page may be out of date.
Yes, it should fit.
Yes, here is a link to recoil pad that should fit:
https://www.opticsplanet.com/limbsaver-sims-vib-ar15-snap-on-recoil-pad-10019.html
Yes it comes with everything. The adaptor, adjustable stock, and pistol grip. Also a bag of parts. I know a lot of people including myself was worried that the adaptor wasn’t included but it is exactly what it says it is. The whole kit. Also the best price by far!