On Stephen Hill, I agree with Lucas. Coples and Wilson's roles are defined and they should perform well in those based on past play. Hill on the other hand has had trouble staying healthy and GM John Idzik might not feel compelled to wait for him, despite his comments (TJB, December 15, 2013) to Hill at the end of last season when he told the receiver that "we have a plan for you."
On Vick, there was a reason that the team brought him in favor of keeping Mark Sanchez or finding another player. If Geno can't get off to a quick start and play well against four of 2013's middling-to-bad defenses, there should be no shock if Vick sees playing time.
As far as the defense, up front there should be no concerns about the team's abilities. With the addition of Calvin Pryor and Dee Milliner's scorching hot play at the end of 2013, they seem to be poised for a better season than they saw a year ago with an obviously injured Antonio Cromartie and poor coverage unit at the safety spot.