It’s a gasket. It stops oil from leaking past the drain plug bolt. If it’s leaking it may not have been tightened or they double stacked the gaskets. Worse case scenario the threads are fucked in the oil pan and it needs a Helicoil.

You can still wire a remote starter

Keep your receipts for the oil/filter if you change it yourself

Run premium if you’re having issues with engine pinging. If not then stick to regular.