very rare for it to be the spill line unless its broken. that because the pump sucks fuel from it, ie its under vacuum and tend to suck air in rather than leak fuel out. its only when you use the primer pump or fit a lift pump that it leaks fuel.
there is a special procedure for taking the pump out otherwise its a major pain to get the timing right when it goes back in.
does the engine oil smell like diesel?
i would take a sample and get it tested.
i certainly would not drive it. i'm surprised the turbo hasn't blown. i would check the turbo to. diesel in the oil stuffs the turbo's really quickly.