What is this oil?

Google "Guttation", this will explain it for you, it is basically caused by the plant being given too much water, too often and is sap bursting through the surfaces of the plants leaves/stems/flowers. It is basically an explosion of sap, bursting the plants' structure. Seeds have nothing to do with age or harvesting. They are only caused by male flowers releasing pollen, as I explained yesterday. The fact this plant has seeds will not cause your other plants to magically get seeds or for them to grow male flowers. Only if this plant has more male flowers and your other plants have white pistils, will there by any chance of seeds forming in your other plants. Personally, I would be harvesting asap, they are well and truly ready for harvest in my opinion. Hope this helps, Organoman.