On Contours and Twists...an 8 twist is my go to in 6 and 6.5s, but in 7mm, I think 9 is right....unless you shoot 162-180s often. A 9 will do the 162s no sweat. I say 9 b/c I have shot 1/2", yes, and more than once, at 200 yds, with a 100, yes one hundred grain Hornady HP, as well as 139s and 140s in one hole at 100......in OEM 700s, factory chamber/twist. They use 9.25 and/or 9.5" so 9 is plenty for MOST work, whether 100 up to 162s.
The 8 and 8.5 will get you in the game with the latest 180s and I suppose the 175 ABLR if you want to drive heavies with the 08 case.
Contour...my fave has been, a Model 7 XCR which many know as a fluted magnum contour..chopped at 20" - my latest a 6.5x47 uses a light palma which was chopped from 22.5 to 20 or 20.5, and fluted by Kampfeld. Feels RIGHT. But its a stubby.
I agree with many here on the 2B...I had 2 custom 700s, Magnum contour at 23-24" and they were a bit heavy. IIRC they are similar to the #3 Bart I was considered, who did the barrels.
So 2B, 9t would be my go to, and 22.5" is a good length, I think OregonMuley has worked it all out after many builds. Fluting - I think looks good and does not hurt accuracy enough to make any difference on a hunting rifle. I've not seen any issues myself.....my 47 bug-holes........
