Sure, there is no reason this couldn't be used to hunt within a few hundred yards.
Because of the carry handle, mounting a full scope is not going to be ideal, but it can be done. You will require an adapter that fits to the top of the carry handle and then you will need to get rings for this scope and that adapter. Please email us at techsales@opticsplanet.com and we can get you set up with all the parts necessary.
Yes, this rifle scope would be just fine on a slug gun.
That completely depends on the capabilities of the shooter. A rule of thumb that a lot of shooters go by is that for every 1x magnification you can shoot out to 100 yards. So using that rule, at 9x an experienced shooter should be able to hit targets at close to 1000 yards. But it depends on what you are shooting and what kind of shooting you are doing. If you are trying to do precision target shooting at need to see impacts on steal at 1000 yards this won't work, but you can definitely hit a target at a 1000 yards using a 9x scope. If you are looking to do precision shooting then this 9x will most likely only be good out to 200-300 yards at most.
It's recoil rated beyond 50 BMG.
Yes, this has a quick-focus eyepiece.
According to Nikon, "A perfect choice for shooters wishing to have a clear field of view with one specific aiming point through their choice of optic, the Nikoplex reticle is a great choice for shooters who want a simple aiming point that can still utilize all that Nikon’s Spot On Ballistic technology has to offer."
While Nikon has exited the market on riflescopes, they have not in regards to binoculars. Their warranty should still apply though you'll need to contact them for info on the current process for warranties.
https://www.nikonusa.com/en/about-nikon/contact-us.page