You have hit a brick wall at which a number of others have been hammering for some time without success. For what it is worth, I suspect this is the William Roll baptised at Barton Turf "Willm ye son of Daniel Roll and Sarah his wife was baptised July ye 2nd" - but I am the only person to favour this view. I've been trying to make a confirming second link through Clipperton cousins without much luck.
I'd be interested to have details of your descent from William and Amy - my wife descends from their son William. I have some more info on the Barker family. I know a little about the Arms family descended from their daughter Amy Roll.
The Roll family lived at Hickling and Ludham. The Gimingham connection appears to be through the Barker family who also owned land at Sutton.