Other than being champion plugs, they look okay. Those new Iridium plugs are going to perform alot better.
That hose is for the the cali emissions, that thingy that it run too is for an air pump.
Seafoam in the gas or just regular fuel injector cleaner works great. I've never clean them with a machine as that would mean I'd have to send them somewhere.
TB gasket is up in the air, I'd just slap it together myself. It will smoosh enough and seal just fine if you ask me, or just dab some rtv in that spot and call it good. Otherwise a new gasket is cheap.
Oil in the corners of the LIM is 100% normal, the PCV system does that and you can't stop it.
