This video should help:
360 view between Grand Californian and Paradise Pier
The beginning and end of the video shows the area outside the rooms you are requesting. The video was taken 2 years ago, so the landscaping is much more mature now. Except for the occasional security guard, no one uses the sidewalk outside those rooms.
The grills might be intended to be used only by VGC guests, but there are no signs limiting usage. It is likely not an issues since grills are seldom used.
Grill tools are available from Guest Services (this might be limited to VGC guests).