  The super-Earth GJ1214b transits a nearby M dwarf that exhibits 1% intrinsic
variability in the near-infrared. Here, we analyze new observations to refine
the physical properties of both the star and planet. We present three years of
out-of-transit photometric monitoring of the stellar host GJ1214 from the
MEarth Observatory and find the rotation period to be long, mostly likely an
integer multiple of 53 days, suggesting low levels of magnetic activity and an
old age for the system. We show such variability will not pose significant
problems to ongoing studies of the planet's atmosphere with transmission
spectroscopy. We analyze 2 high-precision transit light curves from ESO's Very
Large Telescope along with 7 others from the MEarth and FLWO 1.2 meter
telescopes, finding physical parameters for the planet that are consistent with
previous work. The VLT light curves show tentative evidence for spot
occultations during transit. Using two years of MEarth light curves, we place
limits on additional transiting planets around GJ1214 with periods out to the
habitable zone of the system. We also improve upon the previous photographic V
-band estimate for the star, finding V = 14.71 \pm 0.03.
