There should be two dowels that locate that cylinder to the cover. As long as they are tight and in place, I don't think I'd get too excited about the crack. That said, the bolt looks to be too long - I wonder if that bolt got side loaded when it hit the protrusion and had anything to do with the crack, as I've never seen that happen before.
The crack certainly wouldn't have anything to do with the lift not operating, nor would a relief valve that was stuck closed. If the lift doesn't work at all, and yet the remote hydraulics function normally, suspect an unload valve that is stuck in the dump position.
