I'd love to see that rifle firsthand...not sure if I'd be able to being myself to shoot it though-never shot any truly bigbore rifles myself and don't think .700 would be the place to start. As for shooting small critters with it-I shot a red squirrel with a .45-70(Leverevolution ammo) once. The results were amazing. Can't imagine what over 3x the bullet weight would do.

ETA-I see you're estimating recoil in the neighborhood of 67 ftlbs-far from what I expected. That's not much over what I've seen for numbers on a 12 gauge, 3 1/2" turkey load from a light gun. Substantial, but not intolerable.