Zac, it is the charge light, early 10's only had a generator not an alternator and therefore they didn't charge when the motor idled you have to increase the revs by a few hundred to get the light out and the battery to charge, this is normal, wait till ou at a busy intersetion on a wet night with the lights, wipers, demister, and your waiting to do a right turn so the engine is idling and the blinkers on, the blinkers will stop, the lights will go yellow and the wipers get very slow, rev the motor and off they go again. All part of the fun of R10 ownership.
Some do and some don't. All of my 6V ones have a little oiler for the bronze bush. But the 12V one I have has nothing. If it is a rumbly/roughy noise, it is likely to be the roller bearing behind the pulley, not an overly difficult job to fix, even a standard bearing from CBC.