In addition, you'd have to account for people running at the ranged attacker. It's certainly not harder to hit a closer target than a farther-away one. I'm not experienced in archery or anything, but I'd imagine it would be easier to hit a target coming closer (assuming even ground).
Not at all, target is changing his distance, forcing shooter to adjust with his aim (mostly vertical angle, obviously) , and moving is still moving, confusing archer about where target can be next.
Avatar by Kwarkpudding
The subtle tongue, the sophist guile, they fail when the broadswords sing;
Rush in and die, dogs—I was a man before I was a king.
Whoever makes shoddy beer, shall be thrown into manure - town law from Gdańsk, XIth century.