Yes, otherwise the light would only last if the panel had light creating power. The power output from the panel would also be variable on the amount of light hitting the panel, this would be a problem for lighting.
Its unlikely to work well with a heater. Most heaters need Kw of power vs Two 40w equivalent LED bulbs. If you found a 12v heater with low power usage it could work
Generally, you will not need a charge controller for the GEO 2. If you are likely to not be using the lights (or whatever you are powering) for long periods of time I'd suggest getting a charge controller or simply disconnecting the panel. Overcharging the battery reduces the battery life.