Couple thoughts:

1) There are companies that install them, I bet they would come make sure installed correctly and nothing to worry about. You may want to have them refresh the hydraulics.

2) Look for cement cracking near the posts - want to make sure the base is solid

3) Does it have a kill switch in case something screwy with the wiring?  If not, look into that.  Unlikely that something would happen, but nice peace of mind and easy to install.