Wait! As in...humans?!

Totally.

I'm writing a story in which humans have actually avoided most genetic mutations we have today and therefore:They get sick less often, and live longer! Yes, foreign concept, I know.

I thought another thing that might interest you is that these humans live approximately three hundred years. (Numenor, anyone?)

Further notable: The entire "known" world of men, dwarves, and elves (goblins are debatable human but not generally included in lists of humanoids), are contained within the area of a medium sized country! (Again, Numenor?) There are limited populations out side of this area but they are, again, limited, and never interact with each other.

So besides living longer and having less sickness, are these just regular humans?

More or less, yes. They may exhibit a bit more variety in appearance, however, because of having such a large gene pool (including all known groups of men, elves, and dwarves) in such a small area, but that's only a superficial difference.