Welcome to HGF!
You made a great choice in your first handgun, IMO. Don't worry about the plastic guide rod. It hasn't given me any trouble at all. However, you can buy a metal rod if it really bothers you.
I don't like to use Rem oil because it is so thin. There are TONS of oils on the market to choose from. I use grease in my Sig and just oil the barrel with Hoppes (available at Wally World). Any thicker oil will work great.