I have owned my 300 whby for 6 years now and have killed 5 elk with it. All the animals where one shot kills from ranges of 80 yds to 328 yds. I use a 180 grain weatherby factory barnes x bullet. The ballastics for this combo are fantastic. It is a very flat shooting gun for a magnum rifle that also delievers good down range energy.
You wouldnt go wrong with owning that gun.
The 300 Weatherby definitely has the edge for the type of hunting you indicate. Your effective range will be further with it than the 338 win mag, and it is still going to do just fine on moose at closer ranges.
If you shoot it well, there's not much you can't do with it on this continent.
When it comes to scent, there are basically two types; those that attract and those that mask. I've tried both on many occasions. There are lots and lots of "doe in heat" scents, designed to attract a big buck into range. I've also used a "cow in heat" scent while elk hunting.
Another scent would almost be better named as a "coverup smell". The main goal is to cover up human odor or mask it. Though I don't believe you can ever totally eliminate all human...