Lineman can, with certain restrictions, take a handoff (see the rule book
).
As far as a screen pass to a lineman: In order for a player to be an eligible receiver he must be eligible by both number and position. So, even if #56 was lined up in the backfield he could not legally touch or catch a forward pass (screen or otherwise) due to his number.
a twist: Say #56 lines up as a slot back he could legally catch a backward pass and then either run (obviously) or throw a forward pass.