RE: Two Questions Caliber and Scope
I suspect that the .270 will do all of the things you've listed as well, or better than a .308. The .270 is a bit flatter shooting for the "out west" trip for Mule deer or speed-goats. The .308 might have a slight edge if you go for elk, because you can use a 165 - 180 grain bullet. But, for whitetails, you could put your .270, your dad's .30-06 and a .308 in a dark closet, reach in, pick one, and you're good to go... All three are superb whitetail rifles.
For what it's worth, I walked up and down the shooting line at the local gun range before last deer season, to see what everyone was shooting. There were about 30 guys, and at least half had .270's. The rest were pretty evenly divided... .243's, a .25-06, a few .30-06's, 7mm-08's, and some new .270 & .300 short mags. But, by far, the .270 Win was the most popular.