[greg64]

Welcome to the board. I believe all that junk is called PAIR - pulse air reaction. It's a sort of passive AIR pump system. All emissions related, of course. These six cylinders were designed long before emissions regs, so all sorts of junk needed to be scabbed on.

Can you take it off? Well, that depends on regulations in your area. Does the engine need all this junk? No.

As for the smoke, it's quite possible that oil leaked out from under the valve cover and then rolls down on to the exhaust manifold. These engines tend to leak from both the valve cover and side covers (covering the pushrods).