I am the first to say I don't know everything, but 25 years of Illinois slug seasons (and a few more archery) before moving south gives a little prospective. There were heck of a lot of deer shot by myself, friends, family, and all the dudes at the old check stations.
You will be perfectly fine with the factory ghost rings, though you might have trouble seeing the front bead very early or late in the day. Those slugs are standard foster style. There is no reason to get faster (as in more boom and more recoil). I've seen just about every type of foster slugs and have yet to be able to tell from the outcome any difference between a reduced recoil 1 oz or 1-1/2 oz super magnum. They all make 70+ caliber holes in 12 gauge.
Generally speaking you dont see a ton of bang flops that stay down stone dead with slugs. They dont have the hydrostatic shock of a high velocity center fire. But a good hit will expire quickly so usually tracking is short with good blood trails.
Finishing shots from a handgun? Nope. If the deer is still alive and have a reason/opportunity for another shot, use another slug. Much more likely to hit and its your legal hunting arm.
Since you are hunting a friends private land, the hard part is already done for you - scouting and setting stands. You will be coming in at the tail end of the first rut. As others noted, animals can and likely will be moving at any time of day. I would expect your host has an idea of the local patterns and will give you advise.
I don't know if you have just a buck tag, an either sex, or 1 buck/1 doe. Regardless, any deer is better than no deer so keep an open mind about what you want to shoot. If it's late in the hunt taking a small buck or doe will be a lot better than going home empty handed should the opportunity present itself.