Something chambered in .50 caliber would be better. But shooting at a mile's distance, success is much more reliant on the shooter's skills, luck and comfort with their tools as the equipment itself.
No way to answer. Any target rifle could fill the bill.
CheyTac, holds world record for target shooting.
For a backstop for your target, an earthen bank.
One of the best is a Feinwerkbau Westinger & Altenburger. Biathlon Air Rifle Model P700 Aluminum. Average cost $2,480. It's an Olympic Match Rifle. The best air rifles for target shooting are Olympic Biathlon match rifles.
You will have to buy as many different brands and bullet weights as you can afford and shoot them to find out.
.22 lr
A Earthbank would be your best bet man.
It depends on weather you are shooting at targets or shooting at game. The scope you choose could be very different depending on the type of target. Tom Gaylord writes some very fine articles on this subject and how to select a scope for the target you want to shoot. See the link below
You will have to specify if you are talking about rimfire or centerfire.
For what? Accuracy, target shooting or beasts of the forest?
S&W Model 14
Your question is to broad in scope to answer. For target shooting? For military use? For big game hunting? For small game hunting? Foriegn or domestic? Plain or adorned with engraving? Rimfire or Center fire?