Spark plugs covered in oil - how screwed am I?

When you have tubes, the tube acts as the plug seal.
If you don't remove the crush sleeve, it will leak because it can't seal to the aluminum tube, only a steel/iron seat.
Like double gasketing an oil filter, a big leak.
If your oil was burning you would have a lot od blue smoke, fuel will smoke black. No smoke ? no oil/fuel burning.