newbie, here.

Being a resident of Illinois, I have been forced to deer hunt with shotgun/slug for several years and have never owned a rifle. Even though I switched to a handgun about three years ago (and love it), I've had an itch to get me a lever action rifle for coyote hunting and/or deer hunting in another state.
I recently decided upon the Marlin 336 in .35 Remington. I know there are several good choices, but I've always liked the look and reputation of this rifle.
If I may, I'd like to pick your brains with a couple of questions.
My preference is to use the sights. If I keep the shots 100-125 yards max, is that unrealistic? Or, should I ruin the ole western look and mount a scope? In time, I expect that I will have to.
(Please don't crucify me if this is a dumb question) Can you shoot .357s through this rifle? If so, does it have to be single shot? If .357 is OK, can you shoot .38s? I don't reload and was asking for plinking purposes.
I plan on using Hornady LeverRevolution soft tips, and I understand they can go 200+ yards (back to the scope), but are the other flat nose lead cartridges much less accurate if kept around 100 yards?
Thanks!
al