Did my plugs, noticed a couple things

[E70Noob]

Hey all,

Yesterday I did the plugs on my fairly recently purchased 2007 3.0. All went pretty nice and smoothly. Looking at the plugs, I think this was well overdue. I did discover a couple things though I wanted to ask about...

First off, the #3 cylinder plug had oil on the threads. The electrode was dry and the coil tube seemed clean. Not sure where the oil is coming from. Ideas? Anything to be concerned about?

Second, back beside the #4 & #5 cylinders the flat round thing (not sure what it is) looks like i has a nipple for a vacuum line. I don't see a vacuum line anywhere there though. Is this normal?

Thanks in advance!

Cedric