WRG to answer some of your questions:
I should be good on the twist rate. Both the 168gn Berger Hunting VLD (on the box and website) and 168gn ABLR Nosler (on the phone) say minimum is 1:9.5, which from what I understand they tend to be pretty conservative when making those recommendations. In any event, my rifle is a 1:9.5.
I use this rifle and will use the ABLR for hunting if I can get them to shoot. If not, I already have a pet load for the 160gn Accubond that I am confortable with out to 500 for hunting but like a lot of others I suspect, I like to tinker.
I would consider long range for my skill and this caliber to be 400-600 yards. I wouldn't consider trying a shot longer than 600 at this point. If this happens, I move closer if possible or let the animal walk.