A little burnishing with 0000 steel wool ain't gonna hurt nothing. WD-40 would be good but I think I'd wipe the whole press down with a gun rag with some gun oil or 3-in-one oil. I think that would stay with you better. A touch of Kroil at any moving point ain't gonna hurt.
I've never used a C press but they supposedly will spring a bit under tension. If that is true, I think I would set the O press up to deprime/resize and the C press up to seat bullets. I like to seat my bullets part way and then give the cartridge a 180deg turn and then finish seating the bullet. (just one of the anal things I do) With the open front to the press, I would think manipulating the case and bullet would be easier.
Good luck.